Question

Read through the scenarios below and calculate the predicted change in kinetic energy of the object compared to a

50 kg ball traveling at 10 m/s.
A 50 kg ball traveling at 20 m/s would have kinetic energy.
A 50 kg ball traveling at 5 m/s would have kinetic energy.
A 50 kg person falling at 10 m/s would have kinetic energy.

Answer 1

D) 4 times more

E) 4 times less

A) the same

Step-by-step explanation:

Answer 2

The initial scenario is a ball of 50kg traveling at 10m/s

The equation of kinetic energy is: K = (1/2)mv^2

a) A 50 kg ball traveling at 20 m/s would have more kinetic energy.

20m/s is the double of 10 ms, and in the kinetic energy the velocity is squared, so we have:

K = (m/2)(20)^2 = (m/2)(2*10)^2 = (m/2)4*10^2 = 4*((m/2)*10^2)

Here the kinetic energy is 4 times the initial kinetic energy.

b)A 50 kg ball traveling at 5 m/s would have less kinetic energy.

here we do the same process as before,

K = (m/2)(5)^2 = (m/2)(10/2)^2 = (1/4)(m/2)(10)^2

This kinetic energy is one-fourth of the initial kinetic energy.

c) A 50 kg person falling at 10 m/s would have equal kinetic energy.

The kinetic energy only depends on the mass and the velocity, and in this case, the velocity and mass are the same that in the initial case, so here the kinetic energy is the same.