Velocity & Acceleration

BTW you have a Test Thursday September 4th

Velocity

• Both the speed and direction of an object

Speed: A car travels 60km/h

Velocity A car travels 60km/h to the north

WITH DIRECTION

Vector

• Quantities that are fully described by both a magnitude and a direction.

• Force is a vector quantity – it has magnitude and direction

• Velocity is too! It has both magnitude and direction

Scalar

• Quantities that are fully described by a magnitude (or numerical value) alone

• Speed – only has magnitude

Let’s Play Vector or Scalar!

• You just picked up some fellow classmates at chic-fil-a in your new rockin’ sharkmobile. You make the 1 mile drive to CTA for some fun after school learning with Ms. Meyer.

Vector or Scalar?

• You are headed to an Ohio State football game. You bike all 13.8 miles North East to campus.

Vector or Scalar?

• You are standing at the CTA girl’s basketball game. You go nowhere. You want to cheer for your team!

Vector or Scalar?

Constant Velocity

• Remember constant speed? Well this is the same thing but with velocity (a direction)

• Well if there is a direction, and it’s constant, then there has to be a constant direction!

Changing Velocity

• If either the speed or the direction changes (or both) then the velocity changes

• A car on a curved track may have a constant speed but, because its direction is changing, its velocity is not constant. – We will see in the next section that it is accelerating

Acceleration

• So we can change the velocity of something by changing its speed, direction or both

• How quickly velocity changes is acceleration

Acceleration Formula

Or

Acceleration Example

1) A particular car can go from rest to 90 km/h in 10s. What is its acceleration?

A = v-vo/time interval

A = 90-0 / 10s = 9km/h*s

Bozeman Science is the Bomb.com(a little like jmeyerscience.weebly.com)

Bozeman Science - Speed, Velocity, Acceleration

Practice

• Ch. 3 Review Questions pg. 46– # 10, 11, 14

• Ch. 3 Plug & Chug pg. 47– # 10,