Question

1. which activity requires a person to exert force on an object that causes the object to move but does not change the kinetic or potential energy of the object?

a. moving an object to a greater height with acceleration
b. moving an object to a greater height without acceleration
c. carrying an object with acceleration at the same height
d. carrying an object without acceleration at the same height

Explanation:

To solve this, we analyze each option:

• Option a: Moving with acceleration to greater height. Kinetic energy (KE) changes (since acceleration means velocity change) and potential energy (PE) changes (height increases), so energy changes. Eliminate.
• Option b: Moving to greater height without acceleration. PE increases (height up), so energy changes. Eliminate.
• Option c: Carrying with acceleration at same height. Acceleration means net force, so KE changes (velocity change), even at same height. Energy changes. Eliminate.
• Option d: Carrying without acceleration at same height. Force is equal to weight (no acceleration, so net force zero). Height is same (PE constant), and velocity is constant (KE constant, since no acceleration means constant speed). So neither KE nor PE changes, but force is exerted to move it (constant velocity, so force to overcome friction maybe, but energy of the object doesn't change).

Answer:

d. Carrying an object without acceleration at the same height