Physics 7

Which of the following best describes the effect of a force on an object?

• A force can only change the shape of an object.

• A force can change the speed or direction of an object's motion.

• A force only acts on objects in motion.

• A force has no effect on objects at rest.

A box is pushed across a smooth floor with a force of 10 N. If the box moves at a constant speed, what can be inferred about the force of friction acting on the box?

• It is greater than 10 N.

• It is equal to 10 N.

• It is less than 10 N.

• There is no friction acting on the box.

A student observes that a ball at rest on a flat surface does not move. Which of the following forces are balanced in this situation?

• The force of gravity and the applied force.

• The force of gravity and the normal force.

• The normal force and the force of friction.

• The applied force and the force of friction.

Two students are pulling a rope in opposite directions. Student A exerts a force of 15 N to the left, and Student B exerts a force of 10 N to the right. What is the net force, and in which direction does the rope move?

• 5 N to the left

• 5 N to the right

• 25 N to the left

• 25 N to the right

When one team in the tug-of-war suddenly pulls harder than the other, the rope starts moving toward that team. What does this situation demonstrate?

• Balanced forces

• Unbalanced forces

• Magnetic forces

• Equal forces

Which of the following everyday situations involves balanced forces?

• A soccer ball rolling down a hill.

• A person sitting on a chair without moving.

• A swing being pushed and moving back and forth.

• A car accelerating on a straight road.

A person is riding a bicycle at a constant speed on a flat road. Which statement best describes the forces acting on the bicycle?

• The forces are balanced because the speed is constant.

• The forces are unbalanced because the bicycle is moving.

• There are no forces acting on the bicycle.

• Only frictional force is acting on the bicycle.

A soccer ball is kicked, and it rolls across the field. What will happen to the ball if no external force acts on it (e.g., friction or a kick)?

• The ball will keep rolling forever.

• The ball will stop because of unbalanced forces.

• The ball will change direction on its own.

• The ball will bounce off the ground.

In the free-body diagram shown at the right, what is the missing force?

• Weight force

• Normal force

• Frictional force

• Tension force

Which of the following forces is represented by a vertical upward arrow in a free body diagram?

• Friction force

• Normal force

• Tension force

• Gravitational force (weight)