Power, Work, Energy Laborator

Question 1

It is defined as the product of the net force acting on a body and the distance moved in the direction of the force.

Answer 1

work

Question 2

work formula

Answer 2

w = (force)(distance)

Question 3

SI unit for work

Answer 3

joules

Question 4

joules is the unit of what vectors

Answer 4

(N)(m) or kg m^2/s^2

Question 5

Only the component of the applied force (F) in the direction of motion of the lawn mower, ____, is used to do work on the lawn mower.

Answer 5

Fhorizontal

Question 6

given that only Fhorizontal is used, the final formula for work is

Answer 6

W = Fdcosθ

Question 7

An object is moved with a force of 15N across a horizontal surface. How much work is done if the object is moved 50m?

Answer 7

750 joules

Question 8

650 J of work is done in moving a desk in a horizontal distance of 5m. How much force is used to move the desk?

Answer 8

130 N

Question 9

It if the rate at which work is done

Answer 9

power

Question 10

formula of power

Answer 10

W/t

Question 11

SI unit for power

Answer 11

watts

Question 12

watts is a combination of what vectors

Answer 12

joule/sec

Question 13

A force of 150N is used to push a motorcycle 10m along a road in 20 sec. Calculate the power in watts.

Answer 13

W = (150N)(10m) = 1,500 Joules

P = W/t = 1,500 Joules / 20 sec = 75 watts

Question 14

A pump lifts 20Kg of water in a vertical distance of 20m in each sec. What is the power output?

Answer 14

Take note: gravitational acceleration = 9.8 m/sec2

F = (20Kg)(9.8 m/sec2)

F = 196 N

W = (196N)(20m)

W = 3,920 joules

P = 3,920 joules / 1sec

P = 3,920 watts

Question 15

It is the defined as the ability to do work.

Answer 15

energy

Question 16

Two types of energy

Answer 16

kinetic
potential

Question 17

energy in motion

Answer 17

kinetic enegy

Question 18

energy that is stored

Answer 18

potential

Question 19

SI unit of energy

Answer 19

Joules

Question 20

KE is a scalar/vector quantity

Answer 20

scalar quantity

Question 21

formula of kinetic enegy

Answer 21

1/2mv^2

Question 22

What is the kinetic energy of a 60 Kg girl on skis traveling at 20 m/sec

Answer 22

KE = ½ mv2

KE = ½ (60Kg)(20 m/sec)2

KE = 0.5 (60)(400)

KE = 12,000 joules

Question 23

A sports car is moving at 4.0 m/sec. if the mass of the car is 800 Kg, how much kinetic energy does it have?

Answer 23

Solution:

KE = ½ mv2

KE = ½ (800 Kg)(4 m/sec)2

KE = ½ (800)(16)

KE = 6,400 joules

Question 24

is energy of position

Answer 24

gravitational potential energy

Question 25

Potential energy formula

Answer 25

PE = mgh

Question 26

A mass of 100 Kg is lifted a distance of 50m. How much potential energy does it possess?

Answer 26

PE = mgh

PE = (100Kg)( 9.8 m/sec2)(50m)

PE = 49,000 joules

Question 27

The sum of kinetic energy and potential energy in a system is ___, in absence of friction.

Answer 27

constant

Question 28

law of conservation of energy formula

Answer 28

KE + PE = constant

Question 29

law of conservation of energy states

Answer 29

Energy cannot be created or destroyed; it may be transformed from one form to another, but the total amount of energy in a system remains constant.

Question 30

rate at which work is done

Answer 30

power

Question 31

amount of energy delivered when a force movesa an item

Answer 31

work

Question 32

formula of force of spring

Answer 32

Fspring = (k)(x)

where K = spring constant x = distance

Question 33

formula of potential energy of spring

Answer 33

PE = 1/2kx^2