Physics Chapter 2: 1D Kinematics Review

Which of the following quantities has units of displacement?

• A) 32 ft/s2 vertically downward

• B) 40 km southwest

• C) 9.8 m/s2

• D) -120 m/s

Which of the following quantities has units of velocity?

• A) 40 km southwest

• B) 9.8 m/s2 downward

• C) 186,000 mi

• D) 9.8 m/s downward

True or False: If the acceleration of an object is zero, then that object cannot be moving.

• A) True

• B) False

An auto manufacturer advertises that their car can go "from zero to sixty in eight seconds." This is a description of what characteristic of the car's motion?

• A) average speed

• B) average velocity

• C) average acceleration

• D) displacement

An object moving in the +x direction experiences an acceleration of +2.0 m/s². This means the object

• A) travels 2.0 m in every second.

• B) is traveling at 2.0 m/s.

• C) is decreasing its velocity by 2.0 m/s every second.

• D) is increasing its velocity by 2.0 m/s every second.

Suppose that a car traveling to the east (+x direction) begins to slow down as it approaches a traffic light. Which statement concerning its acceleration must be correct?

• A) Its acceleration is in the +x direction.

• B) Its acceleration is in the -x direction.

• C) Its acceleration is zero.

• D) Its acceleration is decreasing in magnitude as the car slows down.

Suppose that an object is moving with a constant velocity. Which statement concerning its acceleration must be correct?

• A) The acceleration is constantly increasing.

• B) The acceleration is constantly decreasing.

• C) The acceleration is a constant non-zero value.

• D) The acceleration is equal to zero.

When a ball is thrown straight up with no air resistance, the acceleration at its highest point

• A) is upward

• B) is downward

• C) is zero

• D) reverses from upward to downward

A rock from a volcanic eruption is launched straight up into the air with no appreciable air resistance. Which one of the following statements about this rock while it is in the air is correct?

• A) On the way up, its acceleration is downward and its velocity is upward, and at the highest point both its velocity and acceleration are zero.

• B) On the way down, both its velocity and acceleration are downward, and at the highest point both its velocity and acceleration are zero.

• C) Throughout the motion, the acceleration is downward, and the velocity is always in the same direction as the acceleration.

• D) The acceleration is downward at all points in the motion.

A 10-kg rock and a 20-kg rock are dropped at the same time and experience no significant air resistance. If the 10-kg rock falls with acceleration a, what is the acceleration of the 20-kg rock?

• A) 4a

• B) 2a

• C) a

• D) a/2