# High School Physics : Using Motion Equations

## Example Questions

← Previous 1

### Example Question #76 : Linear Motion

Peter starts from rest and runs down a hallway 31 seconds. If his final velocity is , what was his acceleration?

Explanation:

We can solve this question using the given initial velocity, final velocity, and time.

### Example Question #77 : Linear Motion

A potted plant falls off a window sill from 3 meters above the ground. How long does it take before the plant hits the ground?

Explanation:

Using the equation above and the given values, we can solve for the time. First we need to find the change in distance.

The plant travels meters in the downward direction. Now we can plug in the given values from the question to solve for time.

### Example Question #3 : Using Motion Equations

Walter throws a disc from 1.5 meters above the ground with purely horizontal motion. How long will it be before the disc hits the ground?

Explanation:

The horizontal motion will not affect the time the disc is in the air. Time will be determined by the rate at which the disc falls: the acceleration due to gravity.

We can solve for the time using the equation below and the values given in the question.

### Example Question #3 : Using Motion Equations

Leslie rolls a ball out of a window from 10 meters above the ground, such that the initial y-velocity is zero. What will the ball's final velocity be right before it hits the ground?

Explanation:

We are given the initial velocity, acceleration, and the initial and final distances.

Using the equation below and the given values, we can solve for the final velocity.

### Example Question #5 : Using Motion Equations

crate slides across a floor for  before coming to rest  from its original position.

What is the initial velocity of the crate?

Explanation:

The problem gives us distance, final velocity, and change in time. We can use these values in the equation below to solve for the initial velocity.

Plug in our given values and solve.

Divide both sides by .

Multiply both sides by .

### Example Question #4 : Using Motion Equations

crate slides across a floor for  before coming to rest  from its original position.

What is the net acceleration on the crate?

Explanation:

All of the equations regarding acceleration require an initial velocity. We will need to solve for the initial velocity using the given variables. The problem gives us distance, final velocity, and change in time. We can use these values in the equation below to solve for the initial velocity.

Plug in our given values and solve.

We can use a linear motion equation to solve for the acceleration, using the velocity we just found. We now have the distance, time, and initial velocity.

Plug in the given values to solve for acceleration.

### Example Question #5 : Using Motion Equations

A ball starts rolling at . It accelerates at a constant rate of  for . What is the final velocity?

Explanation:

To solve for the final velocity, remember that the relationship between velocity, acceleration, and time is .

Using the given values for the initial velocity, acceleration, and time, we can solve for the final velocity.

### Example Question #5 : Using Motion Equations

A book, starting at rest, falls off of a table. What is its velocity after  in motion?

Explanation:

We can solve this question using the equation for acceleration in terms of velocity:

We know our initial velocity (zero, since we start from rest), time, and the acceleration of gravity. Use these values to isolate the variable for the final velocity.

Note that the final velocity is negative, since the book is traveling in the downward direction.

### Example Question #1 : Using Motion Equations

A car traveling along a highway moves at initial velocity  before it begins to accelerate. If it accelerates for  at  , what is the final velocity of the car?

Explanation:

Use the kinematic equation:

We are given the initial velocity, the time elapsed, and the acceleration. Using these values, we can solve for the final velocity.

### Example Question #7 : Using Motion Equations

A particle is traveling north at from an initial position. After traveling  from the initial position, the particle begins accelerating north at  for . What is the final distance between the particle and the initial position?

Explanation:

Utilize the kinematic equation:

The particle's motion can be broken into two parts: the initial distance and the distance traveled during acceleration. The initial distance is given.

The distance during acceleration can be found using the kinematic formula and given values for the initial velocity, acceleration, and time.

Add the two distances together.

Convert the final answer to kilometers.

← Previous 1