### All AP Physics B Resources

## Example Questions

### Example Question #1 : Understanding Vector And Scalar Quantities

A ball is thrown at a velocity of at an angle of from the horizontal. What are the ball's horizontal and vertical velocities?

**Possible Answers:**

There is not enough information to solve this problem

**Correct answer:**

The velocity of can be broken into horizontal and vertical components by using trigonometry. Think of the figure below, where x and y velocity components of the total velocity are shown.

Use the total velocity, the x-component, and the y-component to form a right triangle below.

Treating as the hypotenuse, x-component as the leg adjacent, and y-component as the leg opposite, you can conclude that the velocities are related through trigonometric identities.

Plugging in the given values, we can solve for the x and y velocity components.

### Example Question #1 : Motion

Which answer choice below includes only scalar quantities?

**Possible Answers:**

Force, time, velocity

Acceleration, energy, displacement

Distance, speed, time

Velocity, displacement, force

Displacement, time, acceleration

**Correct answer:**

Distance, speed, time

Scalar quantities are those that can be described with magnitude only, as opposed to vectors, which include both magnitude and direction components. Distance, speed, and time are all scalars. Displacement is not a scalar, as it involves both the distance and the direction moved from a starting point. Velocity also includes a direction component, and is therefore a vector quantity.