Question

Inclined plane question

Answer 1

A 50kg brick starts from rest and slides down a slope converting gravitational potential energy to
kinetic energy. In the process it has to do work against a constant force due to friction of 65N. Air
resistance may be ignored. The slope is 40m long and the top of the slope is 6.0m vertically above the
bottom of the slope. What will be the speed of the block at the bottom of the slope?
A. 16 m/s
B. 11 m/s
C. 4 m/s
D. 0 m/s
E. Cannot be determined form the information given

Answer 2

It asked you to solve this without vectors, if possible (if anything, it makes it much harder)

Answer 3

if theta be the angle of inclined plane with horizontal then net force acting on mass 50 kg is equal to\[F= mg \sin \theta - frictional force\] so by calculation F= 10 N
this force causes acceleration according to relation F=ma .. Here m is 50 kg and F (net force) is calculated to be 10 N.. so acceleration, a= 0.2 m/s2
Now by using relation \[v ^{2}= 2as\] (starting from rest) , we get v (final velocity) = 4m/s