Physics Final Exam

Suppose that an object travels from one point in space to another.  Make a comparison between the displacement and the distance traveled.

• The displacement is either greater than or equal to the distance traveled.

• The displacement is always equal to the distance traveled.

• The displacement is either less than or equal to the distance traveled.

• The displacement can be either greater than, smaller than, or equal to the distance traveled.

When is the average velocity of an object equal to the instantaneous velocity?

• always

• never

• only when the velocity is constant

• only when the velocity is increasing at a constant rate

A new car manufacturer advertises that their car can go "from zero to sixty in 8 s". This is a description of

• average speed

• instantaneous speed

• average acceleration.

• instantaneous acceleration.

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

• traveling at 2.0 m in every second.

• traveling at 2.0 m/s in every second.

• changing its velocity by 2.0 m/s.

• increasing its velocity by 2.0 m/s in every second.

Suppose that a car traveling to the East (+x direction) begins to slow down as it approaches a traffic light.  Make a statement concerning its acceleration.

• The car is decelerating, and its acceleration is positive.

• The car is decelerating, and its acceleration is negative.

• The acceleration is zero.

• A statement cannot be made using the information given.

Suppose that a car traveling to the West (-x direction) begins to slow down as it approaches a traffic light.  Make a statement concerning its acceleration.

• The car is decelerating, and its acceleration is positive.

• The car is decelerating, and its acceleration is negative.

• The acceleration is zero.

• A statement cannot be made using the information given

Suppose that an object is moving with a constant velocity.  Make a statement concerning its acceleration.

• The acceleration must be constantly increasing.

• The acceleration must be constantly decreasing.

• The acceleration must be a constant non-zero value.

• The acceleration must be equal to zero.

If the velocity of an object is zero, does it mean that the acceleration is zero?  Support your answer with an example.

• no, and an example would be an object starting from rest

• no, and an example would be an object coming to a stop

• yes, because of the way in which velocity is defined

• yes, because of the way in which acceleration is defined

Can an object's velocity change direction when its acceleration is constant?  Support your answer with an example.

• No, this is not possible because it is always speeding up.

• No, this is not possible because it is always speeding up or always slowing down, but it can never turn around.

• Yes, this is possible, and a rock thrown straight up is an example.

• Yes, this is possible, and a car that starts from rest, speeds up, slows to a stop, and then backs up is an example.

Suppose that an object is moving with constant acceleration.  Make a statement concerning its motion with respect to time.

• In equal times its speed increases by equal amounts.

• In equal times its velocity changes by equal amounts.

• In equal times it moves equal distances.

• A statement cannot be made using the information given.