Need for Speed
Unit of measurement for speed
m/s or km/hr
What is the term used to describe a change in speed or velocity?
Acceleration
Form of energy associated with motion
Kinetic
Calculate the speed of an object that travels 500m in 10 seconds
50m/s
Form of energy when a rubber band is pulled.
Elastic potential energy
Three variables used to calculate speed
time, distance, speed
Unit of measurement for acceleration
m/s/s or km/hr/hr
Unit of measurement
Joules
Calculate the speed of a train that travels 1.4km in 90 seconds.
15.55m/s or 55.99 km/hr
Formula for Kinetic energy
KE = 1/2 mv2
Latrelle leaves home at 8am and travels the 3km to school. He returns home at 9pm that night after hanging with his homies after school. Calculate his total displacement.
0
Rate of acceleration due to gravity
8.91m/s/s
Joel is too scared to jump off the bungee platform at AJ Hacketts. What form of energy does he have the most of?
Gravitational Potential Energy
Calculate the rate of acceleration of an object that changes from 5m/s to 10m/s in 2 seconds.
2.5m/s2
A car hits a tree. Describe what happens to the energy with at least three specific examples.
Kinetic energy transforms into heat and sound energy.
Kinetic energy transferred from wheels to crumple zones to absorb impact.
Inertia means passenger continues to move forward with kinetic energy. Transferred to seat belt to stop movement.
5km/hr north is an example of?
Vector or velocity
Formula used to calculate acceleration
a = (vf-vi)/t
Formula for GPE
GPE = M x g x h
The mass of an object is 500kgs and it has a GPE of 14000joules. Calculate its height.
2.85m
Calculate the final speed of an object dropped that takes 15seconds to hit the ground.
147.15m/s
Velocity is what type of measurement?
Vector
How to determine if an object is slowing down.
Negative rate of change or acceleration
State the law of conservation of energy and provide an example
Energy is transferred or transformed but is not created nor destroyed
A car stopped at the stop lights reaches a speed of 63km/hr in 8 seconds. Calculate its rate of acceleration.
2.29m/s/s
A car of mass 1200 kg, travelling at a steady speed, has a kinetic energy of 175 kJ. What is the speed of the car?
175 kJ = 175,000 J
�� = 175,000 J
m = 1200 kg
175,000 = 12 x 1200 kg x v2
175,000 = 600 kg x v2
v2 = 175,000�600��
v2 = 291.67
v = 291.67
v = 17.1 m/s
The car has a speed of 17.1 m/s