Let's analyze each question one at a time.
3. Two people collide on a busy city street. What information is needed to calculate the force one of the people exerts on the other person?
The correct answer is:
C) the mass and acceleration of each person.
This is because to calculate the force exerted between them, you would typically use Newton's second law (F = m*a), where you need the mass and the change in velocity (acceleration is the change in velocity over time).
4. A soccer ball rests on the ground in a stationary position. Which of the following best describes the forces acting on the ball?
The correct answer is:
C) balanced forces.
Since the ball is at rest, the forces acting on it (gravity pulling it down and the normal force from the ground pushing it up) are equal in magnitude and opposite in direction, resulting in a net force of zero.
5. Two bowling balls of different masses collide while accelerating at 1.875 m/s^2. The first ball, rolling to the right, weighs 7 kg. The second ball, rolling to the left, weighs 4 kg. What force does the bowling ball weighing 7 kg exert on the bowling ball weighing 4 kg? To find the force exerted by the 7 kg ball on the 4 kg ball, you use Newton's second law (F = m*a). The total force exerted by the first ball can be calculated as:
\[ \text{Force} = \text{mass} \times \text{acceleration} = 7 , \text{kg} \times 1.875 , \text{m/s}^2 = 13.125 , \text{N} \]
Since the 7 kg ball is rolling to the right, the force is acting in that direction. Thus, the correct answer is: C) 13.125 N to the right.