Acceleration

Acceleration

by Armie Estrobo

​After this lesson, you will learn to answer the following questions:

​1. What is an accelerating object?

​

2. What is acceleration and how do you determine its magnitude and direction?

​The object is accelerating if

• Its changing its velocity.​

• Its changing its direction'​

​Sports announcers will occasionally say that a person is accelerating if he/she is moving fast.

​

Yet acceleration has nothing to do with going fast.

​

A person can be moving very fast and still not be accelerating.

​

Acceleration has to do with changing how fast an object is moving. If an object is not changing its velocity, then the object is not accelerating.

Multiple Choice

Why does a car accelerate as it round a corner at a constant speed?

• Its direction changes

• It slows down

• It doesn't

• Its speeds up  

Multiple Choice

When are you NOT undergoing an acceleration in a car?

• speed up

• constant speed

• slow down

• make turns

EQUATION FOR ACCELERATION

​Delta= Change

​Typical Acceleration Units

• ​m/s/s

• ​mi/hr/s

• ​km/hr/s​

​m/s²

​km/hr²

Multiple Choice

The SI unit for acceleration is

• mph

• m/s²

• ft/sec

• m/s

Multiple Choice

.

In each of the following cases, determine where the car has no acceleration?

• A car speeds up after a stoplight turns green.

• A car with the cruise control set at 80 km/h going down a straight highway

• A car slows down as it approaches a red light

• A car turning a curve at a constant speed

​A car accelerates from 12.2 m/s to 28.6 m/s in 2.4 s. Determine the acceleration of the car

​final answer = 6.8 m/s²

​A car accelerates from 12.2 m/s to 28.6 m/s in 2.4 s. Determine the acceleration of the car

​You are driving 75 mph then came to a stop that took you 20 s. Calculate your acceleration

V_f = O mph t = 20 s

​V_i = 75 mph a = ?

​Equation/Formula

​final answer = -3.8 mph/s

Multiple Choice

A negative acceleration means that your object is _____. 

• not accelerating

• speeding up 

• not moving

• slowing down 

Multiple Choice

A positive acceleration means that your object is _____.

• not accelerating

• speeding up

• not moving

• slowing down

Multiple Choice

A rightward-moving motorcycle increases its velocity from 5.0 m/s to 25.0 m/s in 10 s. Find the final velocity?

• 5.0 m/s

• 25.0 m/s

• 10 s

Multiple Choice

You are riding your bike at 9 km/h. Ten minutes later, your speed is 6 km/h. Find the time in this problem.

• 9 km/h

• 6 km/h

• ten minutes

Multiple Choice

Which term defines that the velocity is 0.

• accelerating

• rest

• slowing down

• speeding up

Multiple Choice

A roller coasters accelerates from an initial velocity of of 6.0 m/s to a final velocity of 70 m/s over 4 seconds.  What's the acceleration?

• Incorrect

  24 m/s²

• 16 m/s²

• 18 m/s²

• 16 m/s

Multiple Choice

A car starts from rest at a stop light and reaches 20 m/s in 3.5 s. Determine the acceleration of the car.

• 2.2m/s²

• 5.7m/s²

• 7.0m/s²

• 70m/s²