prep 3 , lesson 2

( Distance-Time) graph for a regular motion at a constant speed is represented by a.........

• straight line parallel to time axis.

• straight line parallel to the distance axis.

• straight line passing through the origin point.

• straight line cuts the time and the distance axis.

The uniform acceleration means that the object speed ...........by equal values through equal periods of time.

• increases only

• decreases only

• increases or decreases

• doesn't change

When an object speed increases, the movement is described as

• uniform speed.

• decelerating motion.

• zero acceleration.

• accelerating motion.

When an object moves with acceleration zero, this means that the

• object's speed is changed.

• object moves with positive acceleration.

• object moves with deceleration.

• object's speed is constant.

Decelerating motion means the...........

• object speed decreases by time.

• object speed is constant.

• object speed increases by time.

• object is at rest.

Acceleration is the

• change in distance in a unit time.

• change in speed in a unit time.

• rate of change of distance relative to the speed.

• change in the position relative to the observer.

the unit of acceleration is

• (m/s²)

• jouls

• m

• s

The rate at which an object changes position is called ..............

• speed

• Time

• Distance

• AAcceleration

An observer in a moving car with 80 km/h was observing a moving car with 90 km/h in the same direction, so the observed speed of the second car is ................. km/h.

• 10

• 80

• 90

• 170

Acceleration: is the rate of change in ___________.

• speed
• distance
• displacment