Acceleration

In each of the following cases, determine where the car has no acceleration ?

• A car shortly after a stoplight turns green.
• A car approaching a red light
• A car with the cruise control set at 80 km/h
• A car turning a curve at a constant speed

In science, acceleration refers to

• increasing speed

• decreasing speed

• changing direction

• increasing speed only

What does it mean when a change in velocity is negative?

• The object is speeding up.

• The object is slowing down.

• The object is changing direction.

• The object is falling down.

Acceleration is

• the rate at which velocity changes.

• the change in velocity

• the rate of change

• when you speed up only

Which of the following is a unit for acceleration?

• km/s
• m/s²
• mi/hr
• ft

If velocity is measured in meters/second and time is measured in seconds, the unit of acceleration is

• m/s/s

• m/s²

• m/s

• m

If velocity is measured in kilometers/hour and time is measured in seconds, the unit of acceleration is

• km/s/s

• km/s²

• km/h/s

• km

If velocity is measured in miles/hour and time is measured in seconds, the unit of acceleration is

• mi/h/s

• mi/s²

• mi/h²

• mi

A car accelerates from a standstill to 70 m/s in 10 seconds.  What is the acceleration?

• 0.7m/s²
• 7m/s²
• 14m/s²
• none of the above

A car starts from rest at a stop light and reaches 20 m/s in 4 s. Determine the acceleration of the car.

• 16 m/s²

• 5 m/s²

• 80 m/s²

• -5 m/s²