Question
a small block of mass m is kept on a rough inclined surface of inclination o * fixed in an elevator the elevator goes up with a uniform velocity v &block doesn't slide on the wedge the w.d by the force of fricition on block in t time is?
ANS) mgtsin2o*
Joshi sir comment
work done by the force of fricition on block in t time = fvtcos(90-θ) = mgsinθvtsinθ 
Read 3 Solution.
the answer is dimensionaly incorrect.
draw the FBD . u will get f =mg sinθ now break f into perpendicular components.
here fsinθ will act in downward drtn. and f cosθ in a direction perpendicular to motion.
so the work will be done by f sinθ.
work done=mgsin2θ * h
h = height travelled in time t
NIKHIL VARSHNEY 12 year ago
is this solution helpfull: 17 20
PARDON , THE ANS IS mgvtsin2o
SARIKA 12 year ago
is this solution helpfull: 11 13
take h = vt
NIKHIL VARSHNEY 12 year ago
is this solution helpfull: 7 8