Question

A ball rolls down a hill at constant velocity. Which of the following conditions must be true?
(1 point)
The ball will accelerate as gravity pulls it down the hill.
The momentum of the ball increases over time.
The ball has no net force acting on it.
There are no forces acting on the ball.

Answer 1

For a ball rolling down a hill at constant velocity, the correct condition is:

**The ball has no net force acting on it.**

Here's why:

1. **The ball will accelerate as gravity pulls it down the hill.** - This statement is false because if the ball rolls at a constant velocity, it is not accelerating.

2. **The momentum of the ball increases over time.** - This statement is also false, as momentum remains constant if velocity is constant.

3. **The ball has no net force acting on it.** - This statement is true. If the ball is rolling at constant velocity, it implies that the forces acting on it are balanced (e.g., the force due to gravity is balanced by friction or other opposing forces).

4. **There are no forces acting on the ball.** - This statement is false because there are still forces acting on the ball (such as gravitational force and friction); however, they are balanced.

Therefore, the only true condition is that **the ball has no net force acting on it.**