Force and Motion Practice

What is the formula for calculating the speed of an object?

• Speed = Distance × Time

• Speed = Distance ÷ Time

• Speed = Time ÷ Distance

• Speed = Distance + Time

Answer explanation

The correct formula for calculating speed is Speed = Distance ÷ Time. This means speed is determined by dividing the distance traveled by the time taken to travel that distance.

Tags

DOK Level 1: Recall

Which of the following is an example of a balanced force?

• A car accelerating on a highway

• A book resting on a table

• A ball rolling down a hill

• A person pushing a shopping cart

Answer explanation

A book resting on a table experiences balanced forces: the downward gravitational force is equal to the upward normal force from the table, resulting in no net force and no movement.

Tags

DOK Level 1: Recall

Calculate the net force acting on an object if two forces of 5 N and 10 N are applied in opposite directions.

• 15 N

• 5 N

• 10 N

• 0 N

Answer explanation

To find the net force, subtract the smaller force from the larger one. Here, 10 N - 5 N = 5 N. The net force acting on the object is 5 N in the direction of the larger force.

Tags

DOK Level 2: Skill/Concept

If a car travels 150 km in 3 hours, what is its average speed?

• 50 km/h

• 45 km/h

• 60 km/h

• 55 km/h

Answer explanation

To find the average speed, divide the total distance by the total time. Here, 150 km ÷ 3 hours = 50 km/h. Thus, the average speed of the car is 50 km/h.

Tags

DOK Level 2: Skill/Concept

Explain why a ball thrown upwards eventually falls back to the ground.

• Due to air resistance

• Because of gravity

• Because of its weight

• Due to its speed

Answer explanation

A ball thrown upwards eventually falls back to the ground because of gravity. Gravity is a force that pulls objects toward the Earth, causing the ball to descend after reaching its peak height.

Tags

DOK Level 3: Strategic Thinking

Which of the following best describes inertia?

• The tendency of an object to change its state of motion

• The tendency of an object to resist changes in its state of motion

• The force that pulls objects towards the Earth

• The speed of an object in a particular direction

Answer explanation

Inertia is defined as the tendency of an object to resist changes in its state of motion. This means that an object at rest stays at rest, and an object in motion continues in motion unless acted upon by an external force.

Tags

DOK Level 1: Recall

A car is traveling at a constant speed. What will happen over time if no unbalanced forces are applied?

• It will decrease

• It will increase in speed

• It will decrease in speed

• It will maintain a contant speed,

Answer explanation

A car traveling at a constant speed with no unbalanced forces will maintain that speed. If unbalanced forces are applied, it will change speed, but the correct choice states it will maintain a constant speed, which is incorrect.

Tags

DOK Level 2: Skill/Concept

Describe how the mass of an object affects its acceleration when a constant force is applied.

• Greater mass results in greater acceleration

• Greater mass results in less acceleration

• Mass does not affect acceleration

• Mass and acceleration are not related

Answer explanation

According to Newton's second law, acceleration is inversely proportional to mass when a constant force is applied. Therefore, greater mass results in lesser acceleration.

Tags

DOK Level 3: Strategic Thinking

What is the unit of force in the International System of Units (SI)?

• Joule

• Newton

• Watt

• Pascal

Answer explanation

The unit of force in the International System of Units (SI) is the Newton. It is defined as the force required to accelerate a one-kilogram mass by one meter per second squared.

Tags

DOK Level 1: Recall

A car is moving at a constant speed of 60 km/h. What can be said about the forces acting on the car?

• The forces are unbalanced

• The forces are balanced

• There are no forces acting on the car

• The car is accelerating

Answer explanation

Since the car is moving at a constant speed of 60 km/h, the forces acting on it must be balanced. This means that the forward force (like engine power) is equal to the opposing forces (like friction and air resistance), resulting in no acceleration.

Tags

DOK Level 2: Skill/Concept