# Velocity & Acceleration

Velocity & Acceleration
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Slide 1: Slide
PhysicsSecondary Education

This lesson contains 17 slides, with text slides.

Lesson duration is: 15 min

## Items in this lesson

Velocity & Acceleration

#### Slide 1 -Slide

No, they are not the same thing...
• Many people confuse the two.
• Velocity is simply the speed of an object in a particular direction.
• Acceleration is the rate of the change in velocity, which means something is either slowing down or speeding up.

#### Slide 3 -Slide

What is Velocity?
• Vector quantity
• Speed at which something moves in a particular direction.
• Measures displacement

#### Slide 4 -Slide

Velocity Formula

v = velocity
d = distance
t = time
v=td

#### Slide 5 -Slide

What is the S.I. Unit for Velocity?

Because:
Unit for distance is m (meters)
Unit for time is s (seconds)
sm

#### Slide 6 -Slide

Let's Practice!
A car travels at uniform velocity a distance of 100 m in 4 seconds. What is the velocity of the car?

First step:
Write the equation for velocity
v=d
t

#### Slide 7 -Slide

Next, define your variables:
d = 100m
t = 4s

Now you can plug your variables into your equation:
v = 100
4

#### Slide 8 -Slide

Work out the problem
v = 100
4

v = 25
sm

#### Slide 9 -Slide

What is Acceleration?
• Vector quantity
•  The rate at which an object changes its velocity over a period of time.

REMEMBER:
Vector quantity of the rate and direction of motion. In simpler terms, it is the speed at which something moves in one direction.

#### Slide 10 -Slide

Acceleration Formula
a = acceleration

v = change in velocity (vf {final} - vi {initial})

t = change in time
(tf {final} - ti {initial})

#### Slide 11 -Slide

What is the S.I. Unit for Acceleration?

(meters per second squared)
Because:
Unit for velocity is
Unit for time is seconds

sm
sm
2

#### Slide 12 -Slide

Keep in mind
• Subtract initial velocity from final velocity. If you do it in reverse, your acceleration will be incorrect.
• If the final velocity is less than the initial velocity, you will have a negative number which means the object slowed down.
• If you do not have a starting time, use zero (0).

#### Slide 13 -Slide

Let's Practice
A delivery truck accelerates from 20       to 40        in 4 seconds. What is its average acceleration?

First, write out your equation

a = v (f) - v (i)
t (f) - t (i)

sm
sm

#### Slide 14 -Slide

Next, define your variables
v (f) = 40
v (i) = 20
t (f) = 4s
t (i) = 0s

sm
sm

#### Slide 15 -Slide

Plug your variables into the equation

a =  40 - 20
4 - 0
a = 20
4
a = 5

sm
2

#### Slide 16 -Slide

CONGRATULATIONS

You have successfully learned about velocity & acceleration.