Question

which type of force moves an object toward the source of the force?
a. balanced
b. friction
c. pull
d. push
when a ball is thrown into the air, which force causes the ball to fall back to the earth?
a. gravity pulls the ball back to the earth.
b. friction pulls the ball back to the earth,
c. magnetic force pushes the ball back to the earth,
d. atmospheric pressure pushes the ball back to the earth.
students are experimenting with a toy car on a smpoth, wooden ramp. they apply force to the back of the car to push it down the ramp. the students measure how fast the car rolls down the ramp.
if the students want to increase the speed of the car down the ramp, what should they do?
a. decrease the angle of the ramp
b. decrease the height of the ramp
c. increase the force applied to the car
d. increase the friction between the car and the ramp
multiple forces, such as gravity and friction, act on a soccer ball when it rolls across a field. which statement best describes how friction affects the motion of the soccer ball?
a. friction causes the ball to bounce.
b. friction causes the ball to increase in speed.
c. friction causes the ball to decrease in speed.
d. friction causes the ball to roll forward then backward.

Explanation:

• Question 1: A pull force moves an object toward the source of the force. Balanced forces result in no net movement. Friction opposes motion. A push moves an object away from the source of the force.
• Question 2: Gravity is the force that pulls objects towards the Earth. Friction opposes motion. Magnetic force acts on magnetic materials. Atmospheric pressure acts uniformly and does not specifically pull the ball down.
• Question 3: Increasing the force applied to the car will increase its acceleration (and thus speed) down the ramp. Decreasing the angle or height of the ramp reduces the component of gravitational force acting along the ramp. Increasing friction opposes motion and reduces speed.
• Question 4: Friction is a force that opposes motion. When a soccer ball rolls, friction acts against its motion, causing it to decrease in speed. It does not cause bouncing (which is due to elastic forces), increase speed, or make the ball roll backward then forward.

Answer:

1. C. pull
2. A. Gravity pulls the ball back to the Earth.
3. C. increase the force applied to the car
4. C. Friction causes the ball to decrease in speed.