Acceleration & Deceleration

What is acceleration?

The rate of change of velocity.

Is velocity a scalar or vector quantity?

Vector quantity (it determines how quickly an object is moving and in what direction).

Is acceleration a scalar or vector quantity?

Vector quantity.

What does an accelerating object do?

Gains speed (speeds up).

What does a decelerating object do?

Loses speed (slows down).

When does acceleration cause velocity to increase?

When the acceleration vector points in the same direction as the velocity vector.

What is positive acceleration?

Acceleration in the same direction as velocity (causes velocity to increase).

When does acceleration cause velocity to decrease (deceleration)?

When the acceleration vector is directed opposite to the velocity vector.

What is negative acceleration?

Acceleration directed opposite to the velocity vector (causes velocity to decrease).

Does the effect of acceleration on velocity depend on whether it is directed up, down, left, or right?

No, it depends on whether it is in the same direction or opposite direction to the velocity.

What does a greater acceleration mean for an object's speed?

The faster it will gain speed (greater rate of speed increase).

In the example, which takes longer to accelerate from 0 to 60 mph: a truck or a sports car?

The truck (60 seconds) vs the sports car (5 seconds).

Which has a greater acceleration: the truck or the sports car?

The sports car.