Physics

A 60 N object moves at 1 m/s, what is its kinetic energy?

3 J (60 N=w=mg; m=10. 1/2 times 6 times 1 squared=3)

How much work is done on a 60 N box of books that you carry horizontally across a 6 M room?

360 J (multiply)

How many joules of work are done on a box when a force of 25 N pushes it 3M?

75 J (multiply)

A small economy car and a limousine are pushed from rest across a parking lot, equal distances with equal forces. which car receives more kinetic energy?

Neither one- they receive the same amount of kinetic energy. (Equal distances+ equal forces= equal energy)

Which has greater kinetic energy, a car traveling at 30 km/h or a half-as massive car traveling at 60 km/h?

The 60 km/h car

The amount of potential energy possessed by an elevated object is equal to...

The work done in lifting it

Energy is changed from one form to another with no net loss or gain; true or false

True

if you lift one load up two stories, how much work do you do compared to lifting one load up only one story?

Twice as much

MATH: What is the work done in lifting 60 kg of blocks to.a height of 20 M?

w=Fd=mgd= 60 times 10 times 20= 12,000 J

it takes 80 J to push a large box 8 M across a floor. assuming the push is in the same direction as the move, what is the magnitude of the force on the box?

10 N (divide)

sue can easily lift a 45 N rock with the help of a lever, when she pushes down with 20 N of force she lifts the rock 0.3 meters. How far does she move her arms to do this?

0.7 M (F1 times D1= F2 times D2

How much farther will a car traveling at 100 k/ms skid than the same car traveling at 50 km/s?

Four times as far (if speed is doubled then its 4x's)

MATH: A toy cart moves with a kinetic energy of 10 J, if its speed is doubled, what will its kinetic energy be?

KE= 1/2mv squared=10, KE2= 1/2m (2v squared)