A 5 kg block accelerates at 3 m/s² across a frictionless floor. What is the net force acting on the block?

8 N 15 N 1.67 N 0.6 N

Which of the following is a non-contact force?

Air resistance slowing a skydiver The tension in a tow rope pulling a car The normal force from the ground on a standing person Gravity pulling a satellite toward Earth

A hockey puck sliding on a perfectly frictionless ice rink is given a push and then released. According to Newton's 1st law, what happens next?

The puck gradually slows down because objects naturally stop moving The puck continues at the same speed in the same direction indefinitely The puck accelerates because nothing is opposing it The puck stops immediately when the pushing force is removed

A 10 kg object and a 2 kg object experience the same net force of 20 N. Which correctly compares their accelerations?

Both objects accelerate at the same rate because they experience the same force The 10 kg object accelerates 5 times faster because it has more mass The 2 kg object accelerates 5 times faster than the 10 kg object The 10 kg object accelerates twice as fast as the 2 kg object

What is inertia?

The force of gravity on an object at rest The tendency of an object to resist changes to its state of motion The acceleration produced by a net force The friction between two surfaces in contact

On a free body diagram of a book resting on a table, which two forces must be equal and opposite if the book is stationary?

Friction to the left and air resistance to the right The gravitational force downward and the normal force upward from the table Tension in the book's spine and the normal force The magnetic force and the electrostatic force

If you double the net force on an object while keeping its mass constant, what happens to its acceleration?

The acceleration halves The acceleration remains the same The acceleration doubles The acceleration quadruples

A car is travelling at 60 km/h on a straight road. The driver takes their foot off the accelerator and the car gradually slows down. What force is primarily responsible for this deceleration?

Gravity pulling the car backward Inertia acting in the backward direction Friction and air resistance The normal force from the road surface

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

The gravitational pull of the Moon on Earth's oceans The magnetic attraction between two fridge magnets separated by air Tension in a cable holding a lift The electrostatic force between two charged balloons

An engineer wants to accelerate a 1200 kg car from rest to 20 m/s in 8 seconds. What average net force is required? (Assume constant acceleration.)

150 N 24 000 N 3000 N 960 N

A free body diagram is most useful for:

Showing the internal structure of a mechanical component Visualising all forces acting on an object and their directions to determine net force Illustrating how electricity flows through a circuit Mapping the chemical bonds within a material