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vovangra [49]
3 years ago
9

A runner whose mass is 54 kg accelerates from a stop to a speed of 7 m/s in 3 seconds. (A good sprinter can run 100 meters in ab

out 10 seconds, with an average speed of 10 m/s.) (a) What is the average horizontal component of the force that the ground exerts on the runner's shoes? (b) How much work is done on the point-particle system by this force?
Physics
1 answer:
Darya [45]3 years ago
6 0

Answer:

a. F=126N

b. E_K=1323J

Explanation:

Given:

m=54kg

v=7 m/s

t= 3s

The runner force average to find given the equations

a.

F=m*a

a=\frac{v}{t}

F=m*\frac{v}{t}=54kg*\frac{7m/s}{3s}

F=126N

b.

Work done by the system by this force so

W=F*d

W=E_K

E_K=\frac{1}{2}*m*v^2

E_K=\frac{1}{2}*54kg*(7m/s)^2

E_K=1323J

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The Energy flux from Star B is 16 times of the energy flux from Star A.

We have Two stars - A and B with 4900 k and 9900 k surface temperatures.

We have to determine how many times larger is the energy flux from Star B compared to the energy flux from Star A.

<h3>State Stephen's Law?</h3>

Stephens law states that if E is the energy radiated away from the star in the form of electromagnetic radiation, T is the surface temperature of the star, and σ is a constant known as the Stephan-Boltzmann constant then-

$\frac{Energy}{Area} = \sigma\times T^{4}

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$\frac{T_{B} }{T_{A} } =\frac{9900}{4900}

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To learn more about Stars, visit the link below-

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