Amber is the color of your energyyyyy...
Work, Work, Work , Worrrrrrrrrrrrrk...
NO ONE MAN SHOULD HAVE ALL THAT POWER
Calculate THIS.
Calculate THAT. (Double points!)
100
Energy is measured in the units
What are joules
100
Work is measured in these units
What are joules
100
Power is measured in these units
What are watts
100
An object with 2 kg of mass sits motionless at a height of 5 m. What is its potential energy?
mgh = (2)(9.8)(5) = 98J
100
An object with a weight of 10 N sits on a 25 m cliffside. What is its potential energy?
mgh = (10N)(25m) = 250 J
200
The energy of motion is known as this
What is kinetic energy
200
A man picks up his son off the ground. Is work done on the child?
Yes
200
This is the formula for calculating power
What is P = W/t
200
An object with a mass of 2 kg falls from a height of 5 meters in 1 second. What is its kinetic energy?
1/2mv2 = (1/2)(2)(52) = 25J
200
An object with a weight of 98 N travels at a speed of 2 m/s. What is its kinetic energy?
m =98/9.8= 10kg
1/2mv2 = (.5)(10kg)(22) = 20 J
300
Energy dependent upon position is known as this
What is potential energy
300
A man is passed his child from his wife who is the same height as him. He walks the child across the room. Is work done on the child?
No
300
The relationship between work and power can be described as this
The greater the work, the greater the power
300
A 100 N force on an object pushes it 20 meters to the right. How much work is done on the object?
W = Fd = (100)(20) = 2000J
300
A crane picks up a wrecking ball weighing 1000 N a total of 12 m. A force of 800N then pushes the wrecking ball to the right 20 m into a brick wall it demolishes. At which point was more work done on the wrecking ball?
Pickup Work = (1000N)(12m) = 12000J
Swing Work = (800N)(20m) = 16000J
400
The formula for gravitational potential energy is this
What is mgh
400
A man walks a tray of drinks across a restaurant. He bumps into a coworker and drops the drinks. When is work done on the drinks?
When the drinks fall from the tray
400
Two people with the same mass walk up the stairs. The first person does so in half the time as the second. Which person generated LESS power?
The second
400
A 1 kg object is carried 15 m to the right at a speed of 3 m/s. How much work is done on the object?
0. The force acting on the object is not in the direction of the motion.
400
A man weighing 40N climbs a set of stairs 10 m high in 8 seconds. Another man weighing 20N climbs the same stairs in 5 seconds. Who generates the most power?
Man 1 = 400J/8s = 50W
Man 2 = 200J/5s = 40 W
500
The formula for calculating kinetic energy is this
What is 1/2mv2
500
A man picks up an axe and throws it into a target 15 feet away. When is work done on the axe?
Both when the man picks up the axe and when it is thrown
500
A 60 Watt lightbulb runs for 120 seconds. A 30 Watt lightbulb runs for 240 seconds. Which one generates more energy?
Neither, they generate the same amount of energy
500
A rock weighing 10 kg falls 10 m. How much work is done on the rock?
W = Fd = (10x9.8)(10) = 980J
500
The object below has an additional force of 50N applied to the right. This object will move 10 m in whatever direction it moves. How much work is done on the object, and in which direction?
W = Fd = (30N)(10m) = 300J, to the right