Question

Two equal forces are exerted for the same length of time on two blocks with different masses M1 and M2 (M2 > M1). Which of the following will describe the change in kinetic energy of the blocks?

A. Both blocks gain the same amount of kinetic energy.
B. The block with mass M1 gains more kinetic energy.
C. The block with mass M2 gains more kinetic energy.
D. Kinetic energy change is unrelated to the masses of the blocks.

Answer 1

The block with smaller mass M1 will gain more kinetic energy than block M2 when equal forces are applied for the same duration because it will reach a higher velocity, resulting in a larger change in kinetic energy.

Step-by-step explanation:

The change in kinetic energy of two blocks acted upon by equal forces for the same time period but with different masses (M1 and M2, with M2 > M1) can be determined by Newton's second law and the work-energy theorem. Assuming there is no friction or other forces acting, the force applied would result in equal acceleration for both blocks since Force = Mass x Acceleration (F=ma). However, because kinetic energy (KE) is directly proportional to the mass and the square of velocity (KE = 1/2 mv2), the block with the smaller mass (M1) will reach a higher velocity in the same amount of time due to the equal force applied. Therefore, the block with mass M1 gains more kinetic energy. Answer B is the correct one: The block with mass M1 gains more kinetic energy.