Work Done, Power & Efficientcy

Question 1

What is the Work Done?

Answer 1

The force needed to move an object over a certain distance.

Question 2

What is the Work Done equation?

Answer 2

Force x Distance in the direction of the distance

Question 3

What is Power?

Answer 3

Is the rate of energy released per second.

Question 4

What is the Power Equation?

Answer 4

Work Done (Energy Transferred) / Time

Question 5

What is Efficiency?

Answer 5

Is the % of useful energy from a total input.

Question 6

What is the Efficiency equation?

Answer 6

Useful energy out / Total energy in x 100

Question 7

Another Efficiency equation?

Answer 7

Useful power transferred / Total Power supplied

Question 8

If there is a box with a mass of 6kg which is lifted upwards of 5m in a time of 3s - Calculate the work done against the force of gravity?

Answer 8

WD = F x d
WD = (6 x 9.81) x 5
WD = 58.86 x 5
WD = 294.3J

Question 9

To calculate the Work Done of a horizontal component what must you do?

Answer 9

Construct a right angled triangle and use trigonometry.

Question 10

What is the Kinetic Energy equation?

Answer 10

0.5 x m x v*2

Question 11

What is the GPE Equation?

Answer 11

m x g x h

Question 12

What is special about the GPE and KE Equation?

Answer 12

KE = GPE

Question 13

What does Potential Energy mean?

Answer 13

Stored energy

Question 14

If a ball is resting on the top of a hill what energy does it have?

Answer 14

Gravitational Potential Energy

Question 15

If a ball is push off the top of the hill what does the Gravitational Potential Energy turn into?

Answer 15

Kinetic Energy

Question 16

What happens to the speed of rollercoaster carts as they climb back up a hill?

Answer 16

Cars slow down as some of the KE is turned into PE