Question

two lugboats carrying per tanker - Google Search UB Phys 207 <HMK #10: Work Exercise 6.10 - Enhanced - with Feedback Part A A 15.0 kg package in a mail-sorting room slides 3.00 m down a chute that is inclined at 55° below the horizontal. The coefficient of kinetic friction between the package and the chute's surface is 0.30. Calculate the work done on the package by friction Express your answer with the appropriate units. 'HA OB ? W;- Value Units Submit Request Answer Part B Calculate the work done on the package by gravity. Express your answer with the appropriate units. W.- Value Units Submit Request Answer

Answer 1

a) Ffriction = u*m*g*cos(theta)
= 0.3*15*9.8*cos(55 degrees)
= 25.29Newtons
Friction due to gravity

Pecknfge

Wf = F*d = 25.3*-3 = -75.88 joules Answer.

(negative because it is in the opposite direction as the motion of the package).

B)

Fnet = Fgravity - Ffriction

Fnet = m*g*sin(theta) - u*m*g*cos(theta)
= 15*9.8*(sin(55degrees) - 0.3*cos(55degrees))
= 120.24Newtons
net work is F*d = 120.24* 3 = 360.73 joules

work done by gravity is the combined work to overcome the frictional force and give it net work, so 360.73+ 75.88 = 436.60 joules....Answer.

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