Identify the following quantities as scalar or vector: the mass of an object, the number of leaves on a tree, wind velocity.

Identify the following quantities as scalar or vector: the speed of a snail, the time it takes to run a mile, the free-fall acceleration.

How many displacement vectors shown in the figure above have horizontal components?

How many displacement vectors shown in the figure above have components that lie along the y-axis and are pointed in the –y direction?

Which displacement vectors shown in the figure above have vertical components that are equal?

An airplane with a mass of 1.20  10^4 kg tows a glider with a mass of

Acceleration is defined as

• a rate of displacement

• the change in velocity

• the rate of change of displacement

• the rate of change of velocity

What does the graph above illustrate about acceleration?

• The acceleration varies

• The acceleration is zero

• The acceleration is constant

• The acceleration increases then becomes constant

What is the speed of an object at rest?

• 0.0 m/s

• 9.8 m/s

• 1.0 m/s

• 9.81 m/s

Which of the following is a physical quantity that has both magnitude and direction?

• vector

• resultant

• scalar

• frame of reference