What is a force?

A push or pull that can change motion, speed, direction, or shape of an object.

True or False: Force only needs magnitude to be completely described.

False. Force needs both magnitude and direction to be completely described.

The SI unit of force is _____.

Newton (N)

Which instrument is used to measure the magnitude of force?
A) Thermometer
B) Spring balance
C) Ruler
D) Stopwatch

B) Spring balance

What happens when two equal forces act in opposite directions?

The forces are balanced and the net force is zero.

Two forces of 8 N and 3 N act in the same direction. What is the net force?

11 N in the same direction as both forces.

Why do objects eventually stop moving on surfaces?

Because friction acts opposite to motion and gradually slows them down.

True or False: Smoother surfaces have more friction than rough surfaces.

False. Smoother surfaces have less friction than rough surfaces.

What does Newton's First Law state about objects at rest?

Objects at rest remain at rest unless a net force acts on them.

An object moves with constant velocity. What is the net force?
A) Zero
B) Positive
C) Negative
D) Cannot determine

A) Zero

Complete the formula: F = _____

Ma (mass × acceleration)

What is one newton of force defined as?

Force that produces 1 m/s² acceleration on 1 kg mass.

The value of acceleration due to gravity (g) is approximately _____ m/s².

9.8

Why do airbags reduce injury during car crashes?

They increase impact time, which reduces the force on passengers.

True or False: A heavier object falls faster than a lighter object.

False. All objects fall with same acceleration due to gravity.

If applied force equals friction force, what happens to the object?

The object moves with constant velocity or remains stationary.

What does Newton's Third Law state?
A) F = ma
B) Objects resist motion changes
C) Every action has equal opposite reaction
D) Friction opposes motion

C) Every action has equal opposite reaction

When you walk forward, which direction do you push the ground?

Backward

A 2 kg object accelerates at 5 m/s². What is the applied force?

10 N

True or False: Action and reaction forces act on the same object.

False. They act on different objects.

Why doesn't Earth move noticeably toward a falling apple?

Earth's huge mass makes its acceleration extremely small and unnoticeable.

What type of graph shows constant velocity motion?

Horizontal straight line on velocity-time graph.

Forces of 12 N right and 5 N left act on a box. What is the net force?

7 N toward the right

Riddle: I oppose motion but help you walk. Without me, you'd slip. What am I?

Friction

A rocket moves upward by pushing _____ downward.

Gases

What happens to acceleration if force doubles but mass stays same?

Acceleration doubles

True or False: Gravitational acceleration depends on object's mass.

False. It's same for all objects regardless of mass.

Why do cricket players pull hands back when catching?

To increase catching time and reduce force on hands.

An object needs _____ net force to maintain constant velocity motion.

Zero

What is the weight of a 5 kg object? (g = 10 m/s²)

50 N