Where on the physical activity pyramid do sedentary activities belong?

Hello. This question is incomplete. The full question is:

You've recently read about a chemical laser that generates a 20-cm-diameter, 25.0 MW laser beam. One day, after physics class, you start to wonder if you could use the radiation pressure from this laser beam to launch small payloads into orbit. To see if this might be feasible, you do a quick calculation of the acceleration of a 20-cm-diameter,  100 kg,perfectly absorbing block. What speed would such a block have if pushed horizontally 108 m along a frictionless track by such a laser?

Answer:

V = 0.408 m / s

Explanation:

First, it is necessary to find the radiation pressure on the surface. You will find it using the following formula:

P = P / (πr ^ 2) c

where P is the pressure and c is the speed of light in vacuum

P = 25 * 10 ^ 6 / π (0.2 / 2) ^ 2 * (3 * 10 ^ 8) = 2,652 N / m ^ 2.

Then you must calculate the force (F) and the acceleration (a). This is done through the formulas:

F = P * (πr ^ 2)

F = 2,652 * π * (0.2 / 2) ^ 2 = 0.083N

a = F / m

a = 0.083 / 100 =  0.0002129 m / s ^ 2

You can now calculate the speed.

V = √2ad

V = √2 *0.0002129 * 108

V = 0.2144  m / s

Answer: please find the answer in the explanation.

Explanation:

The direction of the magnetic field at the location of the charge due to the current-carrying wire can be determined by using right hand rule.

The thumb points in the direction of current while the fingers curl around in the direction of the magnetic field.

The right hand rule applies to a current in a straight wire. The thumb is pointed in the direction of the current and the fingers then give the direction of the magnetic field lines.

Answer:

4 seconds

Explanation:

Given:

v₀ = 20 m/s

v = 0 m/s

a = -5 m/s²

Find: t

v = at + v₀

0 m/s = (-5 m/s²) t + 20 m/s

t = 4 s

Answer: I added a picture of the answer

Explanation: its right

The image of answer with labeled Time-Distance Graph is attached.

What is speed?

Speed is distance travelled by the object per unit time. Due to having no direction and only having magnitude, speed is a scalar quantity With SI unit meter/second.

How far an object has moved in a certain amount of time is displayed on a distance-time graph. The graph that shows the results of the distance vs time analysis is a straightforward line graph.

When the object's motion is uniform, and the graph is a straight line.  we can determine the object's speed at any given moment of time from the graph. The object was in the following positions when it started and stopped:

Speed = (Final Position-Initial position)/Time

Drawing a rectangle anywhere along the straight line that regulates the object's speed will reveal the slope of the line. A horizontal line on the distance-time graph indicates that an object is at rest if it is not moving.

Learn more about speed here:

https://brainly.com/question/28224010

#SPJ5

Given :

Speed of bus for first 16 hours is , u = 15 km/h .

Distance he walked for next 0.4 hour is , v = 4.5 km/h .

To Find :

The average speed for the whole  journey.

Solution :

Average speed is given by :

[tex]v_{avg}=\dfrac{u_1t_1+u_2t_2}{t_1+t_2}\\\\v_{avg}=\dfrac{15\times 16 + 4.5\times 0.4}{16+0.4}\\\\v_{avg}=14.74\ km/h[/tex]

Therefore , the average speed of the journey is 14.74 km/h .

Hence , this is the required solution .

Answer:

A critical angle of 60.1°

Explanation:

Let's say

n1 Refractive index of rarer medium

n2 Refractive index of denser medium

So using the relation

စc= Sin^ -1(n1/n2)

So

စc = Sin^-1(1.3/1.5) = 60.1°

Answer:

Total distance covered (scalar quantity) = 23 km

Displacement (vector quantity) = 3 km north from the original starting point

Explanation:

Since he drove 13 km north and then 10 km south, the total distance he cover in his drive was: 13 km + 10 km = 23 km

On the other hand, his displacement was 3 km north from where he started.

Answer:

The  value  is   [tex]t = 3.28 \  s[/tex]

Explanation:

From the question we are told that    

      The  initial velocity is  [tex]u = 23.8 \  m/s[/tex]

       The angle is [tex]\theta=  42.5^o[/tex]

Generally from the projectile motion equation we know that the time of flight is mathematically represented as

       [tex]t  =  \frac{2 *  u  *sin (\theta )}{ g }[/tex]

=>    [tex]t =  \frac{ 2 *  23.8 *  sin (42.5)}{9.8 }[/tex]

=>      [tex]t = 3.28 \  s[/tex]

Answer:

s = d/t

Explanation:

s= speed

d = distance traveled

t = time elapsed

Answer:

See attached image for the requested graphs.

Part 1 : Vector sum is about 9.4 cm long in the graph, from components: about 9.35 cm long. Percent difference = 0.5%

Part 2: Vector sum is about 7.6 cm long in the graph and from components: 7.57 cm long. Percent difference = 0.4%

Explanation:

Part 1.

The graphical addition of the three vectors A, B and C gives a vector sum of approximately 9.4 cm at an angle of about 84 degrees

The component form addition is

Ax + Bx + Cx  = 3.5 + 0 + (-2.5)  = 1

Ay + By + Cy  = 2.0 + 3 + 4.3  = 9.3

Magnitude: [tex]\sqrt{1^2+9.3^2} \approx 9.35\,\,cm[/tex]

The percent difference is: (9.4-9.35) * 100 /9.35 = 0.5%

Part 2.

The graphical addition of the four vectors (A, B, C, and D) measures approximately  7.6 cm at an angle of about 124 degrees.

The component form addition is

Ax + Bx + Cx + Dx = 3.5 + 0 + (-2.5) + (-5.2) = -4.2

Ay + By + Cy + Dy = 2.0 + 3 + 4.3 + (-3) = 6.3

Magnitude = [tex]\sqrt{(-4.2)^2+6.3^2} \approx 7.57\,\,cm[/tex]

The percent difference is: (7.6-7.57) * 100 /7.57 = 0.4%

Answer:

The object will hit the ground at 882.77 m from the lunch

Explanation:

we are to find the range of the motion

What is range?

It is the distance from the point of projection to the point where the object hits the ground

R=(v^2sin2θ)/g

Given data

v= 100 m/s

θ= 30 degree

g= 9.81 m/s^2

Substituting to find the R we have

R= 100^2 *sin(2*30)/9.81

R= (10000*0.866)9.81

R= 8660/9.81

R= 882.77 m

Answer:

Explanation:

We shall apply Gauss's theorem for electric flux to solve the problem . According to this theorem , total electric flux coming out of a charge q can be given by the following relation .

∫ E ds = q / ε

Here q is assumed to be enclosed in a closed surface , E is electric intensity on the surface so

∫ E ds represents total electric flux passing through the closed surface due to charge q enclosed in the surface .

This also represents total flux coming out of the charge q on all sides .

This is equal to q / ε where ε is a constant called permittivity  which depends upon the medium enclosing the charge . For air , its value is 8.85 x 10⁻¹² .

If charge remains the same but radius of the sphere enclosing the charge is doubled , the flux coming out of charge will remain the same .

It is so because flux coming out of charge q is q / ε . It does not depend upon surface area enclosing the charge . It depends upon two factors

1 ) charge q and

2 ) the permittivity of medium  ε  around .

Answer:

Only the perpendicular component of gravity is responsible for the rotation because wind points toward the pivot.

Explanation:

Answer:

Noise in the environment

Electrons emitted via the photoelectric effect

Explanation:

Physical entropy can be seen as a disorderliness that can be observed in a physical system. The noise in a physical system can be used for secure number generation because of its randomness.

Noise is known to have no defined pattern and hence, can be used to creates secure random key generations.

Electrons emitted via the photoelectric effect: Electrons are emitted in a random order whenever a beam of light is incident on a photoelectric material. These electrons emitted can be used for random key generations

Answer:

1500 m/s squared

Hope this helps :)

Explanation:

Explanation:

Given:

v₀ = 10 m/s

v = 20 m/s

t = 60 s

Find: v_avg and Δx

v_avg = ½ (v + v₀)

v_avg = ½ (20 m/s + 10 m/s)

v_avg = 15 m/s

Δx = v_avg t

Δx = (15 m/s) (60 s)

Δx = 900 m

Answer:

Explanation:

Can you please place the square roots in a proper manner so I may assist you?

Answer:

The second leg of the triangle is 35.62

Explanation:

Given that

Hypotenuse = 37

A leg = 10

Based on the above information

The second leg of the triangle is

According to the Pythagorean theorem

a^2 + b^2 = c^2

where,

a and b = legs

And, the c = hypotenuse.

Now put these values to the above formula

So,

10^2 + b^2 = 37^2

b^2 = 37^2 - 10^2

b^2 = 1269

b = sqrt(1269)

b = 35 .62

Hence, the second leg of the triangle is 35.62

The other leg is 35 mm.

Answer:

It depends on what the parachute is made out of.

Explanation:

explanation

a=average velocity/average time

average velocity=0.0+1.2+2.4+3.6/4

average velocity=7.2/4

average velocity=1.8 m/s

average time=0.0+3.0+6.0+9.0/4

average time=18/4

average time=4.5 s

a= average velocity/average time

a=1.8/4.5

a=0.4 m/s²

Answer:

the second derivative of y with respect to time gives the transverse acceleration of an element on a string as a wave moves along an x axis along the string

Explanation:

This is because the transverse wave movement of particles take place in direction 90° to direction of movement of the wave (x) itself, so second derivative of y with respect to time (t)is what will be required

Answer:

5.4atm ,66.5°c

Explanation:

Note that we are given the initial temperature to constant,

Thus PV = constant

so volume halved means pressure doubled from P1v1= p2v2

Hence P2 = 2.7*2atm = 5.4atm

next step we keep pressure constant thenV/T = constant

so volume halved means temperature also halved from V1/T1= v2/T2

Hence

T = 133/2 = 66.5°C

Explanation:

HERACLITUS ALSO SPELLED HERADEITUS, [ BORN C.540 bce, EPHESUS, ANATOLIA [ NOW SELCUK, TURKEY] - DIED C.486 ] GREEK PHILOSOPHER REMEMBERED FOR HIS COSMOLOGY, IN WHICH FIRE FORMS THE BASIC MATERIAL PRINCIPLE OF AN ORDERLY UNIVERSE . LITTLE IS KNOWN ABOUT HIS LIFE, AND THE ONE BOOK HE APPARENTLY WROTE IS LOST.

Answer:

hello your question is incomplete attached below is the remaining part and the solution

Explanation:

The accelerations at points 1,2,3 is zero and this is because the velocities at points 1,2,3 are constants.  attached below is the velocity vector diagram and the acceleration vectors

Answer:

a)  a = 6.31 10¹⁰ m / s² , b) t = 2.06 10⁻⁵ s , c)  x = 13.39 m , d)  ΔK = 1.41 10⁻¹⁵ J

Explanation:

a) Since they indicate that the speeds are non-relativistic, we can use the kinematics relations and Newton's second law

                  F = m a

The force in electrical is

                 F = qE

                qE = m a

                a = qE / m

we calculate

                a = 1.6 10⁻¹⁹ 660 / 1.673 10⁻²⁷

                a = 6.31 10¹⁰ m / s²

b) Let's use the one-dimensional kinematics relation

                 v = v₀ + a t

as part of rest its initial velocity is zero

                 v = a t

                 t = v / a

                 t = 1.30 10⁶ / 6.31 10¹⁰

                 t = 2.06 10⁻⁵ s

c) We use the kinematics displacement equation

                 x = v₀ t + ½ a t²

initial velocity is zero

                x = ½ a t²

                x = ½ 6.31 10¹⁰ (2.06 10⁻⁵)²

                x = 1,339 10¹ m

                x = 13.39 m

d) the kinetic energy is

            ΔK = Kf -K₀

            ΔK = ½ m v² - 0

            ΔK = ½ 1.673 10⁻²⁷ (1.30 10⁶) 2

            ΔK = 1.41 10⁻¹⁵ J

Answer:

Explanation:

Temperature of air = 18°C = 273 + 18 = 291 K .

volume = 500 cc = 0 .5 litre .

pressure = one atmosphere ( atm) .

From gas equation , we can calculate this volume at NTP  as follows.

volume = .5 x ( 273 / 291  ) litre

= 0.469 litre .

In any gas at NTP , 22.4 litre contains 6.02 x 10²³ molecules

.469 litre will contain  6.02 x 10²³ x .469 / 22.4 molecules

= 126 x 10²⁰ molecules .

b )

one mole = 6.02 x 10²³ molecules

6.02 x 10²³ molecules  has weight of 28.96 grams

126 x 10²⁰ molecules has weight of 28.96 x 126 x 10²⁰ / 6.02 x 10²³ grams

= .606 gram .

c )

volume of all the air in the atmosphere = volume of sphere

=  4 / 3 x π  x R³

= ( 4 / 3) x 3.14 x (999.5 x 10³ )³ m³

= 4.18 x 10¹⁸ m³

density of air = 1.225 kg / m³

mass of air = 1.225 x 4.18 x 10¹⁸ kg

= 5.12 x 10¹⁸ kg

d )

volume of air inhaled by 7 billion people

= . 5 x 7 x 10⁹ litre

= 3.5 x 10⁶ m³ .

Total volume of air in atmosphere = 4.18 x 10¹⁸ m³

required percentage

= 3.5 x 10⁶ x 100 /  4.18 x 10¹⁸

= .8373 x 10⁻¹⁰ % .

Answer:

The speed is 10 m/s

Explanation:

Th mass if the rock = 100 g = 0.1 kg

The kinetic energy = 5.0 J

speed of the rock = ?

The kinetic energy of the rock is given by the equation

E = [tex]\frac{1}{2} mv^{2}[/tex]

where

m is the mass of the rock

V is the velocity of the rock

substituting, we have

5 = [tex]\frac{1}{2} *0.1*v^{2}[/tex]

[tex]v^{2}[/tex] = 5/0.05 = 100

v = [tex]\sqrt{100}[/tex] = 10 m/s

Complete Question

A small metal sphere, carrying a net charge q1=−2μC, is held in a stationary position by insulating supports. A second small metal sphere, with a net charge of q2= -8μC and mass 1.50g, is projected toward q1. When the two spheres are 0.80m apart, q2 is moving toward q1 with speed 20ms−1. Assume that the two spheres can be treated as point charges. You can ignore the force of gravity.The speed of q2 when the spheres are 0.400m apart is.

Answer:

The value [tex]v_2 = 4 \sqrt{10} \ m/s[/tex]

Explanation:

From the question we are told that

   The  charge on the first sphere is  [tex]q_1 = 2\mu C = 2*10^{-6} \ C[/tex]

    The charge on the second sphere is  [tex]q_2 = 8 \mu C = 8*10^{-6} \ C[/tex]

     The  mass of the second charge is [tex]m = 1.50 \ g = 1.50 *10^{-3} \ kg[/tex]

      The  distance apart is  [tex]d = 0.4 \ m[/tex]

      The  speed of the second  sphere is  [tex]v_1 = 20 \ ms^{-1}[/tex]

Generally the total energy possessed by when [tex]q_2[/tex] and  [tex]q_1[/tex] are separated by [tex]0.8 \ m[/tex] is mathematically represented

     [tex]Q = KE + U[/tex]

Here KE   is  the kinetic energy which is mathematically represented as

     [tex]KE = \frac{1 }{2} m (v_1)^2[/tex]

substituting value

     [tex]KE = \frac{1 }{2} * ( 1.50 *10^{-3}) (20 )^2[/tex]

     [tex]KE = 0.3 \ J[/tex]

And  U is  the  potential  energy which is mathematically represented as

        [tex]U = \frac{k * q_1 * q_2 }{d }[/tex]

substituting values

       [tex]U = \frac{9*10^9 * 2*10^{-6} * 8*10^{-6} }{0.8 }[/tex]

      [tex]U = 0.18 \ J[/tex]

So

       [tex]Q = 0.3 + 0.18[/tex]

       [tex]Q = 0.48 \ J[/tex]

Generally the total energy possessed by when [tex]q_2[/tex] and  [tex]q_1[/tex] are separated by [tex]0.4 \ m[/tex] is mathematically represented

         [tex]Q_f = KE_f + U_f[/tex]

Here [tex]KE_f[/tex] is  the kinetic energy which is mathematically represented as

     [tex]KE_f = \frac{1 }{2} m (v_2^2[/tex]

substituting value

     [tex]KE_f = \frac{1 }{2} * ( 1.50 *10^{-3}) (v_2 )^2[/tex]

     [tex]KE_f = 7.50 *10^{ -4} (v_2 )^2[/tex]

And  [tex]U_f[/tex] is  the  potential  energy which is mathematically represented as

        [tex]U_f = \frac{k * q_1 * q_2 }{d }[/tex]

substituting values

       [tex]U_f = \frac{9*10^9 * 2*10^{-6} * 8*10^{-6} }{0.4 }[/tex]

      [tex]U_f = 0.36 \ J[/tex]

From the law of energy conservation

     [tex]Q = Q_f[/tex]

So

    [tex]0.48 = 0.36 +(7.50 *10^{-4} v_2^2)[/tex]

   [tex]v_2 = 4 \sqrt{10} \ m/s[/tex]

Answer:

it is correct to conclude that rats prefer food A over food B

the standard deviation is zero

Explanation:

In the experiment performed when both meals are available, rats prefer food A and eat only B when no other is available.

Therefore it is correct to conclude that rats prefer food A over food B

This conclusion is correct because ours is significant with a population of 50 animals all have the same preference for which the standard deviation is zero

Answer:In physics, energy is the quantitative property that must be transferred to an object in order to perform work on, or to heat, the object.[note 1] Energy is a conserved quantity; the law of conservation of energy states that energy can be converted in form, but not created or destroyed. The SI unit of energy is the joule, which is the energy transferred to an object by the work of moving it a distance of 1 metre against a force of 1 newton.

Common forms of energy include the kinetic energy of a moving object, the potential energy stored by an object's position in a force field (gravitational, electric or magnetic), the elastic energy stored by stretching solid objects, the chemical energy released when a fuel burns, the radiant energy carried by light, and the thermal energy due to an object's temperature.

Mass and energy are closely related. Due to mass–energy equivalence, any object that has mass when stationary (called rest mass) also has an equivalent amount of energy whose form is called rest energy, and any additional energy (of any form) acquired by the object above that rest energy will increase the object's total mass just as it increases its total energy. For example, after heating an object, its increase in energy could be measured as a small increase in mass, with a sensitive enough scale.

Living organisms require energy to stay alive, such as the energy humans get from food. Human civilization requires energy to function, which it gets from energy resources such as fossil fuels, nuclear fuel, or renewable energy. The processes of Earth's climate and ecosystem are driven by the radiant energy Earth receives from the sun and the geothermal energy contained within the earth.

Explanation:

Some forms of energy (that an object or system can have as a measurable property)

Type of energy Description

Mechanical the sum of macroscopic translational and rotational kinetic and potential energies

Electric potential energy due to or stored in electric fields

Magnetic potential energy due to or stored in magnetic fields

Gravitational potential energy due to or stored in gravitational fields

Chemical potential energy due to chemical bonds

Ionization potential energy that binds an electron to its atom or molecule

Nuclear potential energy that binds nucleons to form the atomic nucleus (and nuclear reactions)

Chromodynamic potential energy that binds quarks to form hadrons

Elastic potential energy due to the deformation of a material (or its container) exhibiting a restorative force

Mechanical wave kinetic and potential energy in an elastic material due to a propagated deformational wave

Sound wave kinetic and potential energy in a fluid due to a sound propagated wave (a particular form of mechanical wave)

Radiant potential energy stored in the fields of propagated by electromagnetic radiation, including light

Rest potential energy due to an object's rest mass

Thermal kinetic energy of the microscopic motion of particles, a form of disordered equivalent of mechanical energy

Main articles: History of energy and timeline of thermodynamics, statistical mechanics, and random processes