Answer:
Archaeology
Explanation:
Radioisotopes are radioactive atoms of an element in which their atoms contain excess energy making them unstable. When broken down they become more stable releasing radiations.
Carbon 14 is a radioactive isotope that is used in archaeology to study and estimate the lifespan and age of organic materials such as wood, leather. Carbon 14 can be used to estimate the ages of materials up to 50000 to 60000 years.
Answer:
archaeology
Explanation:
Can you solve this question please help me with this
Answer:
Explanation:
The velocity ratio of a wheel and axle is the ratio of the radius (R) of the wheel to the radius (r) of the axle. It is expressed as;
VR = R/r
Since radius = diameter/2
VR = (D/2)/(d/2)
VR = D/d
D is the diameter of the wheel and 'd' is the diameter of the axle.
Given VR = 3 and d = 5cm
3 = D/5
D = 15 cm
If the diameter of the wheel is 15cm, the radius of the wheel will be 15/2 = 7.5cm.
b) Workdone by the load = Load * distance moved by load
Given load = 60kg
Distance moved by load = 2π*radius of axle
Distance moved by load = 2π(0.025) = 0.157
workdone by load = 60* 0.157 = 9.42J
Effort = Workdone by load/distance moved by the wheel
Effort = 9.42/2π(0.075)
Effort = 9.42/0.471
Effort = 20kg
Hence the effort applied is 20kg
c) MA = Load/Effort
MA = 60/20
MA = 3
d) Efficiency = MA/VR * 100%
Efficiency = 3/3 * 100%
Efficiency = 100%
i) A 100 W and 60 W bulb are joined in series and connected to the mains. Which bulb will glow brighter? Why? ii) A 100 W and a 60 W bulb are joined in parallel to the mains. Which bulb will glow brighter? Why?
Answer:
i) 60 W
ii) 100 W
Explanation:
In each case, the bulb that dissipates the most power is the bulb that glows brighter. Power is voltage times current (P = VI). Using Ohm's law, we can rewrite this as P = I²R or P = V²/R.
Bulbs are rated at a certain power for a certain voltage. P = V²/R, so the bulb with the lower resistance will have the higher power rating. Therefore, the 100 W bulb has a lower resistance than the 60 W bulb.
i) They are in series, so they have the same current. P = I²R, so the bulb with the higher resistance will glow brighter. That's the 60 W bulb.
ii) They are in parallel, so they have the same voltage. P = V²/R, so the bulb with the lower resistance will glow brighter. That's the 100 W bulb.
The ways to measure the mass and volume of irregular object
Answer:
When we have irregular objects, it may become very hard to calculate the volume of the object, as we actually can not use any simple equation to find it.
The mass is less tricky, just find a scale and wheight it, now we know the mass of the irregular object.
One way to measure the volume of the object is using water... how we do it?
Get some recipient with water, measure the height of the water.
Introduce your object into the water and totally submerge it, now the level of the water will rise. This is because as you introduce the object under the water, you are displacing up a given volume of water that has the same volume as the irregular object.
Now that you know the height of the water before and after you put your object, you can easily calculate the volume of water displaced, and that will be the volume of the object (the tricky part may be totally submerging the object if, for example, is wood and it floats, here you can use a thin wire to push it down but it will affect a little bit the measures.)
Distinguish between concave mirror and convex mirror
Answer:
Concave mirror makes someone looking at it look dwarf or short, while convex mirror stretches the person making the person look weird.
If an object floats, the volume of the displaced water is equal to the volume of the whole object. True or false?
Answer:
True
Explanation:
This is in fact what the Archimedes principle states, and what he used in the famous anecdote about finding if the crown of the King was really made of gold.
Distance travelled by a free falling object in the first second is: a) 4.9m b) 9.8m c) 19.6m d) 10m
In free fall
[tex]\boxed{\sf s=-\dfrac{1}{2}gt^2}[/tex]
[tex]\\ \sf\longmapsto s=-\dfrac{1}{2}\times 9.8(1)^2[/tex]
[tex]\\ \sf\longmapsto s=-4.9(1)[/tex]
[tex]\\ \sf\longmapsto s=-4.9m[/tex]
Take it positive[tex]\\ \sf\longmapsto s=4.9m[/tex]
Option a is correctThe moving bicycle moves for sometime even after stopping the paddling.why
Answer:
when you are paddling the push carry on when you paddle the hard put on the push.
Answer:
Because of inertia
Explanation:
As stated in Newton first law "An object at rest will stay at rest, an object in motion will stay in motion unless it is acted upon by a force."
For an example:
If you have a drink without a lid in a car and a car suddently the car stop, u will automatically try to catch the drink preventing it from spilling. This is because that the drink that was in motion with the car want to stay in motion, but when the car stop, the drink still wanna be in motion, that's why it will be flying off and spill if u don't catch it.
Back to the question:
if a bicyccle is in motion, it will wants to be in motion untill a force act upon it, let's say a bump or fricition.
hope this help. give me the brainliest if u can.
1. A physical quantity P is related to four observables a, b and c as follows: P= (a3b 2 /c4 ) The percentage errors of measurements in a, b and c are 1%, 4% and 2% respectively. What is the percentage error in quantity P?
Answer:
The percentage error in quantity P is 19%.
Explanation:
It is given that,
A physical quantity P is related to four observables a, b and c as follows:
[tex]P=\dfrac{a^3b^2}{c^4}[/tex]
The percentage errors of measurements in a, b and c are 1%, 4% and 2% respectively.
We need to find the percentage error in quantity P. It is given by :
[tex]\dfrac{\Delta P}{P}\times 100=(3\times \dfrac{\Delta a}{a}+2\times \dfrac{\Delta b}{b}+4\times \dfrac{\Delta c}{c})\\\\=3\times 1+2\times 4+4\times 2\\\\\dfrac{\Delta P}{P}\times 100=19\%[/tex]
So, the percentage error in quantity P is 19%.
Will mark as BRAINLIEST....... The Displacement x of particle moving in one dimension under the action of constant force is related to the time by equation 4x³+3x²-5x+2 , where x is in meters and t is in sec. a)Find velocity of particle at i) t=2 sec ii) t=4 sec. b) Find the acceleration of the particle at t=3 sec.
Explanation:
It is given that,
The Displacement x of particle moving in one dimension under the action of constant force is related to the time by equation as:
[tex]x=4t^3+3t^2-5t+2[/tex]
Where,
x is in meters and t is in sec
We know that,
Velocity,
[tex]v=\dfrac{dx}{dt}\\\\v=\dfrac{d(4t^3+3t^2-5t+2)}{dt}\\\\v=12t^2+6t-5[/tex]
(a) i. t = 2 s
[tex]v=12(2)^2+6(2)-5=55\ m/s[/tex]
At t = 4 s
[tex]v=12(4)^2+6(4)-5=211\ m/s[/tex]
(b) Acceleration,
[tex]a=\dfrac{dv}{dt}\\\\a=\dfrac{d(12t^2+6t-5)}{dt}\\\\a=24t+6[/tex]
Pu t = 3 s in the above equation
So,
[tex]a=24(3)+6\\\\a=78\ m/s^2[/tex]
Hence, this is the required solution.
Will mark as BRAINLIEST......
A balloon is ascending at the rate of 4.9 m/s. A packet is dropped from from the balloon when situated at a height of 100m.
How long does it take the packet to reach the ground ?
What is it's final velocity ?
Answer:
t = 5.04secsv = -44.49m/sExplanation:
Given parameters
initial velocity u = 4.9m/s
height of drop H = 100m
acceleration due to gravity g = -9.8m/s²(since the body is ascending i.e moving against gravity)
Required
time taken by the packet to reach the ground 't'
Using the equation of motion
S = ut+1/2gt²
0-100 = 4.9t+1/2(-9.8)t²
-100 = 4.9t-1/2(9.8)t²
-100 = 4.9t-4.9t²
4.9t-4.9t² +100 = 0
4.9t²-4.9t² -100 = 0
Multiplying through by 10
49t²-49t-1000 = 0
Using the general equation t = (-b±√b²-4ac)/2a
t = -(-49)±√(-49)²-4(49)(-1000)/2(49)
t = 49±√(2401+196000)/2(49)
t = 49±√(198401)/98
t = 49±√(198401)/98
t = 49±449.42/98
t = (49+449.42)/98
t = 494.42/98
t = 5.04secs
Hence, it took the packet 5.04secs to reach the ground
The final velocity is calculated using the formula v = u + at
v = u-gt
v = 4.9-(9.8)(5.04)
v = 4.9-49.392
v = -44.492m/s
This shows that the final velocity is 44.49m/s(moving downwards)
When the hydraulic conductivity Ks = 10 mm/hr; effective matrix potential Ns = 20 mm, and rainfall intensity I = 30 mm/hr , determine the amount of runoff generated when the runoff rate reaches 15 mm/hr?( 2.7 mm or 0.21 mm or 18 mm or 0.67 mm)
Answer:
[tex]t = 0.75 \ hr = 0.75 *60 = 45 \ minutes[/tex]
Explanation:
From the question we are told that
The hydraulic conductivity is [tex]Ks = 10\ mm/hr[/tex]
The effective matrix potential [tex]Ns = 20 \ mm[/tex]
The intensity of rainfall is [tex]I = 30 \ mm/hr[/tex]
The runoff rate [tex]R = 15 \ mm/hr[/tex]
Generally the run off rate is mathematically represented as
[tex]R = (I - Ks) t[/tex]
Here t is the amount of runoff generated
=> [tex]15 = (30 - 10) t[/tex]
=> [tex]t = 0.75 \ hr[/tex]
converting to minutes
[tex]t = 0.75 \ hr = 0.75 *60 = 45 \ minutes[/tex]
solve 1 for x if a=-9.8, v=2.7, and t= 35
Answer:
6097 = x
Explanation:
x = VT + at²/2
x= 2.7 * 35 + 9.8 * (35)²/2
x=6097
Lyla walks three times per week for 45 minutes at a speed of 4.0 miles per hour. She wants to increase her time what should she do
Answer:
C. Walk four times per week
Explanation:
If she wants to increase her time then, she has to walk four times per week.
What is speed?The total distance covered by any object per unit of time is known as speed. It depends only on the magnitude of the moving object. The unit of speed is a meter/second. The generally considered unit for speed is a meter per second.
The mathematical expression for speed is given by
speed = total distance /Total time
As given in the problem Lyla walks three times per week for 45 minutes at a speed of 4.0 miles per hour. She must walk four times a week if she wants to extend her time.
Thus, the correct answer is option C.
Learn more about speed from here, refer to the link;
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The question is incomplete, the complete question is,
Lyla walks three times per week for 45 minutes at a speed of 4.0 miles per hour. She wants to increase her time. What should she do?
A. Walk at 4.5 miles per hour.
B. Walk for 50 minutes.
C. Walk four times per week.
D. Walk up and down more hills.
You have a reservoir held at a constant temperature of –30°C. You add 400 J of heat to the reservoir. If you have another reservoir at 0°C, how much heat must you add to it so that both reservoirs have the same increase in entropy?
Answer:
449.38 J
Explanation:
ΔS = ΔQ/T
Where ΔS = entropy change
Q = quantity of heat
T = temperature
First reservoir :
T = –30°C = - 30 + 273 = 243K
Q = 400 J
Second reservoir :
T = 0°C = 273K
Q =?
To have same increase in entropy for both reservoirs :
Q/T of first reservoir = Q/T of second reservoir
400/243 = Q/273
243 * Q = 400 * 273
Q = (400 * 273) / 243
Q = 109,200 / 243
Q = 449.38271
Q = 449.38 J
Explain.
4. State the limitations of our senses to obtain accurate in
formation concerning
our environment.
Answer:
The limits of our senses are
Limits of Sight
Our vision field of view is 120° sideways and 135° vertically
Angular visual resolution is about an 1/60 of one degree
The presence of blind spots in the eyes
Limits of sound
The hearing range is within 20 - 20,000 Hz and our threshold hearing above 0 to 5 decibel of sound
Limits of taste
We have very limited sense of taste which is partly dependent on our sense of smell with little objectivity in distinguishing tastes
Sense of smell
The establishing of the effectiveness of human sense of smell is gauged on numerous parameters with certain tests being inconsistent, as such, it is difficult to clearly establish the effectiveness of the human sense of smell
In comparison with the sense of smell of other living things such as dogs, the human sense organ is comparatively low
Explanation:
Which element has atoms with valence electrons in a higher energy level than those of calcium (Ca)?
(1 point)
oxygen (O)
lithium (Li)
bromine (Br)
cesium (Cs)
Lithium element contains one electron therefore valence electron will be one.
The highest level of energy is due to valence electrons which are available to the atom.
The calcium has 2 valence electrons which has electrons with high energy.
These energy will be used by the electron during the chemical reaction, and they will either lose or gain valence electron.
Learn more at https://brainly.com/question/24373314
Answer:
calcium
Explanation:
2 electron
what does the area under a distance-time graph signify?
Explanation:
The area under a displacement vs time graph is the absement.
prove p=f/a science chapter pressure
Explanation:
Let 'F' be force acting perpendicularly, 'A' be the area and 'P' be the pressure exerted.
Then,
Pressure is directly proportional to the the force acting perpendicularly i.e.
P ∝ F ............. (i)
Pressure is inversely proportional to the area on which force acts i.e.
P ∝ 1/A ........... (ii)
Combining equations (i) and (ii),
P ∝ F/A
or, P = K × F/A [where K is a constant]
If F is 1N, A is 1m² and P is 1 N/m², then K is 1.
So, P = F/A proved...
Describe the following as a (a) distance (b) speed (c) acceleration (d) force
6. Force
7 speed
8 distance
9 acceleration
explain radiation and which is the hotest source in the world
Ramsar has the highest level of natural radiation in the world.
Hot springs located in the Arkaroola Wilderness Sanctuary in Southern Australia are also credited with higher than normal radiation levels, due to spring water coming in contact with rocks rich in uranium and radon.
2. State Newton's third law of motion.
Answer:
Action and reaction are equal but act in opposite directions
Answer:
Newton’s third law of motion states that “ for every action there is always an equal and opposite reaction.”
Explanation:
If body A exerts a force on body B, then body B will exert an equal and opposite force on body A. It is also called action reaction force. They have equal magnitude but are opposite in direction.
a busis moving with the initial velocity 10m/s . after 4 seconds, the velocity becomes 30m/s . find the acceleration produce by bus,......please I need help
Answer:
5 m/s²
Explanation:
Use the acceleration formula: [tex]a=\frac{v_f-v_i}{t}[/tex]
a = acceleration (m/s²)vf = final velocity (m/s)vi = initial velocity (m/s)t = time (s)Based on the information given to us by the prompt, we know:
vi = 10 m/svf = 30 m/st = 4 sSubstitute these values for the variables to calculate the acceleration:
[tex]a=\frac{30-10}{4}\\\\a=\frac{20}{4}\\\\a=5[/tex]
Therefore, the acceleration of the bus is 5 m/s².
An object has a kinetic energy of 8.8J, and a mass of 450g. How fast is the object moving?
Answer:
The formula for KE is
We have everything we need to solve for the velocity, but we first have to convert the mass from grams to kg:
450 g = .450 kg
and we'll rearrange that and solve it for v before we do any math:
so
v = 6.3 m/s rounded to the correct number of sig fig's
7. Describe about the difficultites that would arise due to lack of non-uniformity in measurement.
Answer:
Many difficulties would arise if there was a lack of uniformity in the measurement of various weights and measures between business, industry, individuals and countries. The biggest implications for a lack of uniformity are in health and safety, equity and sustainability.
Explanation:
palike nlng po
A 92.45 kg baseball player slides to a stop at third base. The coefficient of kinetic friction between the player and the ground is
0.68. Her speed at the start of the slide is 6.87 m/s.
(a) Calculate her acceleration during the slide.
(b) How long (in time) does she slide until she stops?
a) Her acceleration during the slide is -6.67 m/s².
b) She slides 1.03 seconds until she stops.
a) We can find her acceleration during the slide with Newton's second law:
[tex] F = ma [/tex]
Where:
F: is the force
m: is the mass = 92.45 kg
a: is the acceleration =?
The force acting on the baseball player is equal to the friction force ([tex]F_{\mu}[/tex]), and it is negative because it is in the opposite direction to the motion:
[tex] -\mu N = ma [/tex]
[tex] -\mu mg = ma [/tex]
[tex] a = -\mu g [/tex]
Where:
N: is the normal force = mg
μ: is the coefficient of kinetic firction = 0.68
g: is the acceleration due to gravity = 9.81 m/s²
Hence, her acceleration during the slide is:
[tex] a = -0.68*9.81 m/s^{2} = -6.67 m/s^{2} [/tex]
b) We can calculate how long does she slide until she stops with the following kinematic equation:
[tex] v_{f} = v_{0} + at [/tex]
Where:
[tex] v_{f} [/tex]: is the final speed = 0 (when she stops)
[tex] v_{0} [/tex]: is the initial speed = 6.87 m/s
t: is the time =?
Then, the time is:
[tex] t = -\frac{v_{0}}{a} = -\frac{6.87 m/s}{-6.67 m/s^{2}} = 1.03 s [/tex]
You can learn more about Newton's second law here: https://brainly.com/question/19860811?referrer=searchResults
I hope it helps you!
displacement is the _quantity
Answer:
vector quantity
I hope it's hepl u
A box with mass of 2 kg is pushed directly horizontally over a horizontal surface (with friction) at a constant speed of 10 m/s. The force of the push is 60 N. How much thermal energy is generated pushing the box a distance of 15 m
Answer:
E= 600 W
Explanation:
Given that
m = 2 kg
Speed , v= 10 m/s
Force , F= 60 N
Given that box is moving with constant velocity, it means that friction force will be 60 N.
f = 60 N
Therefore total energy generated
E= f x v
E= 60 x 10 = 600 W
E= 600 W
Thus the answer will be 600 W.
A glacier advances at 7.4 x 10^-6 cm/s
How far will it move in 4.2 y?
Answer in units of cm.
cm/s.
Answer:
236.8 cm
Explanation:
1 yr = 365 days = (365×24×60×60) secs
= 32 × 10^6
distace = velocity × time
= 7.4 × 10^-6 × 32 × 10^6
= 236.8 cm
The glacier will move 976.8 cm when it advances at 7.4 7.4×10⁻⁶ cm/s in 4.2 y
From the question above when we talk about how far, is still the same as distance.
Applying the equation of velocity,
V = d/t................... Equation 1
Where V = velocity, d = distance, t = time
make d the subject of equation 1
d = Vt................ Equation 2
From the question,
Given: V = 7.4×10⁻⁶ cm/s, t = 4.2 year = (4.2×3.154×10⁷) seconds = 1.32×10⁸ seconds
Substitute these values into equation 2
d = (7.4×10⁻⁶)(1.32×10⁸)
d = 9.768×10² cm
d = 976.8 cm
Hence the glacier will advances 976.8 cm
Learn more about distance here: https://brainly.com/question/22491931
A drone has been designed that can do monitoring and surveillance at considerable heights due to its light weight of 0.800 kg. For this purpose, they are doing a test to determine its maximum height and they make it start in a vertical direction, using its thrusters it manages to achieve a thrust of 35.0 N during the first 6.00 s. until the battery runs out. What was the maximum height that the drone reached?
Answer:
2660 m
Explanation:
Sum of the forces in the first 6.00 s:
∑F = ma
F − mg = ma
35.0 N − (0.800 kg) (10 m/s²) = (0.800 kg) a
a = 33.75 m/s²
The height it reaches during this time is:
Δy = v₀ t + ½ at²
Δy = (0 m/s) (6.00 s) + ½ (33.75 m/s²) (6.00 s)²
Δy = 607.5 m
The velocity it reaches is:
v = at + v₀
v = (33.75 m/s²) (6.00 s) + 0 m/s
v = 202.5 m/s
After the battery runs out, the drone is in free fall. At the highest point, the velocity is 0. The height at this point is:
v² = v₀² + 2aΔy
(0 m/s)² = (202.5 m/s)² + 2 (-10 m/s²) (h − 607.5)
h ≈ 2660 m
Because the neutron has no charge, its mass must be found in some way other than by using a mass spectrometer. When a neutron and a proton meet (assume both to be almost stationary), they combine and form a deuteron, emitting a gamma ray whose energy is 2.2233 MeV. The masses of the proton and the deuteron are 1.007 276 467 u and 2.013 553 212 u, respectively. Based on this data, what is the mass of the neutron
Answer:
Explanation:
Energy of gamma ray = 2.2233 MeV
Let mass of neutron be n amu
mass defect of deuteron = 2.013553212 - ( 1.007 276 467 + n ) u .
in terms of energy this mass defect will be equal to energy of gamma ray
1 amu = 931 MeV
931 [ 2.013553212 - ( 1.007 276 467 + n ) ] = 2.2233
( 1.007 276 467 + n ) - 2.013553212 = .00238807733
n = 1.008664822 amu
so mass of neutron = 1.008664822 amu