Posted by Anonymous on .
An 85.7 N box of clothes is pulled 26.2 m up
a 31.7
◦
ramp by a force of 112 N that points
along the ramp.
The acceleration of gravity is 9.81 m/s
2
.
If the coeﬃcient of kinetic friction between
the box and ramp is 0.24, calculate the change
in the box’s kinetic energy.
Answer in units of J

physics 
Elena,
ΔKE=ΔPE +W(fr)= m•g•s•sinα+μ•m•g•s•cosα=
=m•g•s(sinα+μ•cosα)