Acceleration, Free Fall & Motion Graphs

What is acceleration

The rate at which velocity changes over time

What is the formula for acceleration

a = (final velocity minus initial velocity) divided by time

What is the SI unit for acceleration

Meters per second squared (m/s²)

What are three ways an object can accelerate

Speed up, slow down, or change direction

Can an object accelerate while moving at constant speed

Yes. It accelerates if its direction changes

A car speeds up from 4 m/s to 24 m/s in 5 s. Find its acceleration

4 m/s²

A cyclist slows from 18 m/s to 6 m/s in 3 s. Find its acceleration

−4 m/s²

An object starts at rest and accelerates at 3 m/s² for 8 s. What is its final velocity

24 m/s

A car moving at 30 m/s slows at −5 m/s² for 4 s. What is its final velocity

10 m/s

An object changes velocity from 12 m/s to 28 m/s with acceleration 4 m/s². How long does this take

4 s

An object moving at 20 m/s reaches rest with acceleration −2 m/s². How long does it take

10 s

What is free fall

Motion when gravity is the only force acting on an object

What is the acceleration due to gravity near Earth's surface

Approximately 9.8 m/s² downward

Ignoring air resistance, what happens to the acceleration of a falling object as it speeds up

It remains approximately 9.8 m/s² downward

What does the slope of a distance-time graph represent

Speed for a straight segment

What does the slope of a position-time graph represent

Velocity

What does the slope of a velocity-time graph represent

Acceleration

What does the area under a velocity-time graph represent

Displacement

What does a horizontal position-time graph mean

The object's position is constant, so it is at rest

What does a horizontal velocity-time graph mean

Velocity is constant and acceleration is zero

What does a horizontal acceleration-time graph at zero mean

Acceleration is zero

A velocity-time graph rises from 5 m/s to 17 m/s over 4 s. What is the acceleration

3 m/s²

An object moves at a constant velocity of 6 m/s for 7 s. What is its displacement

42 m

If velocity is negative, must an object be slowing down

No. Negative velocity indicates direction based on the chosen reference axis

An object has zero acceleration. Must it be at rest

No. It can move at constant velocity