A delivery truck from the postal service is traveling with constant velocity up
ID: 1355652 • Letter: A
Question
A delivery truck from the postal service is traveling with constant velocity up an interstate entrance ramp with a 7.5° slope. A 60-kg box sits on the floor of the truck and as a result of static friction, it does not slide.
(a) During an interval in which the truck travels 310 m up the ramp entrance, what is the net work done on the box?
(b) What is the work done on the box by the force of gravity?
(c) What is the work done on the box by the normal force?
(d) What is the work done on the box by the force of friction?
Explanation / Answer
given ,
mass(m) = 60kg
theta = 7.5 degrees
distance(d) = 310 m
a)
Net work done on the box is "zero"
Because the change in kinetic energy is zero
==============================================
b)
Work done = -m*g*h*sin theta
= - 60 * 9.8 * 310 * sin 7.5
= - 23,792.314 J
===================================================
c)
work done on the box by the normal force is "zero"
direction of motion is perpendicular to force
==============================================
d)
work done on the box by the force of friction
W = mass*gravity*sin theta *h
= 60*9.8*sin 7.5 * 310
= 23,792.314 J
===========================================
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.