Sam is getting ready for a big date when he realizes that he has no money. His roommate, Bill, also has no money, but he has a credit card. Knowing that nobody will let Sam use Bill’s credit card, Sam asks Bill to pull out a cash advance for $120.00. Bill agrees under the condition that Sam is responsible for all interest that accrues on the cash advance which is a 30% interest rate, compounded monthly. The $120 cash advance is repaid in monthly installments over 5 years. How much should Bill ask Sam to pay in interest for the cash advance? a. $3.88 b. $112.80 c. $120.00 d. $232.80

first let us lay out the formula for potential

and kinetic energy:

pe = mgh

ke = (mv^2)/2

where: m=mass, v=velocity, g=gravitational

acceleration, h=height

calculating for mass using the known values of

pe:

340j = m (9.81 m/s^2) (50ft) (1m/3.28ft)

m = 2.27 kg

the law of conservation of energy states that

energy is neither created nor destroyed. therefore, the change in kinetic

energy from 50 ft to 35 ft would be equal to the change in potential energy

from 50 ft to 35 ft. however it would be opposite in signs since one is losing

while other is gaining.

ke(35ft) – ke(50ft) = - [ pe(35ft) – pe(50ft]

ke(50ft) = 0 since the brick is initially at rest

ke(35ft) = 340j - 2.27kg (9.81 m/s^2) (35ft)

(1m/3.28 ft)

ke(35ft)

= 102.38 j