Assume the bike has a mass of 20 kg and is moving down at -9 m/s when it is thrown off the balcony. When the bike hits the ground it still has a mass of 20 kg but the bike is not longer moving. What is the change in momentum of the bike?

180 kgm/s

Explanation:

From Newton's second law of motion,

ΔM = m(v-u) Equation 1

Where ΔM = change in momentum of the bike, m = mass of the bike, v = final velocity of the bike, u = initial velocity of the bike.

Given: m = 20 kg, u = -9 m/s, v = 0 m/s ( the bike is no longer moving)

Substitute into equation 1

ΔM = 20[0-(-9)]

ΔM = 20(9)

ΔM = 180 kgm/s.

Hence the change in momentum of the bike = 180 kgm/s

! 55 !  

write a paragraph or story to explain the transformation between potential and kinetic energy as shown in your picture or model.  

you should have at least 5 complete sentences with a main idea and supporting details.  

you must include the following words:  

potential energy

kinetic energy

mechanical energy

conservation of energy

dude, this is hard lol : ))

it takes about 30 days for it to break down