Chapter 3

Vector A⃗ , which is shown in the figure, has a magnitude of 10 and a direction angle of 60º. What is the magnitude and direction angle (as measured counterclockwise from the positive x-axis) of −A⃗ /2?

5, 240º

Starting from your campsite you walk 3.0 km east, 6.0 km north, 1.0 km east, and then 4.0 km west. How far are you from your campsite?

6.0 km

In the study of physics, what distinguishes a scalar from a vector?

A scalar is specified with a single number, but a vector is specified using both a magnitude and a direction.

A football player kicks a football in a field goal attempt. When the football reaches its maximum height, what is the relationship between the direction of the velocity and acceleration vectors? Assume air resistance is negligible.

At the maximum height, the velocity and acceleration vectors are perpendicular to each other.

Which of the following is a vector? Distance Mass Temperature Displacement Speed

Displacement

For general projectile motion, which of the following best describes the horizontal component of a projectile's acceleration? Assume air resistance is negligible.

The horizontal component of a projectile's acceleration is zero.

For general projectile motion, which of the following best describes the horizontal component of a projectile's velocity? Assume air resistance is negligible.

The horizontal component of a projectile's velocity remains a nonzero constant.

For general projectile motion, which of the following best describes the vertical component of a projectile's acceleration? Assume air resistance is negligible.

The vertical component of a projectile's acceleration remains a nonzero constant.

A bullet fired from a rifle begins to fall

as soon as it leaves the barrel.