Posted by Amisha on Monday, April 9, 2012 at 12:15pm.
The "normal force" is always perpendicular to the direction of motion, and does no work. Zero.
The normal force is M*g*cos53 = 47.2 N
The friction force is 0.40 times the normal force, or 18.9 N
After sliding down a vertical distance
H = 2.00 sin 53 = 1.597 m,
Work done by gravity = MgH = 125.2 J
Work done by friction
= -18.9 * 2.00 = -37.8 J
Net work done on the package
= 87.4 J
Normal force is perpendicular to the displacement of the package; therefore, its work is zero.
The net work is equal to the difference between of the work of gravity and the work of the friction force
W(g) =m•g•h = m•g•s•sinα = 8•9.8•2•sin53 =125.2 J
W(fr) = F(fr) •s =k•N•s=k•m•g•cos α•s = 0.4•8•9.8•0.6•2 =37.75 J.
W = W(g)+ W(fr) =125.2 - 37.75= 87.45 J
Related Questions
physics - An 8.00kg package in a mail-sorting room slides 2.00 m down a chute ...
Physics - A 6.7 kg package starts from rest and slides down a mail chute that is...
physics - A 5.30 kg package slides 1.57 m down a long ramp that is inclined at ...
physics - A 5.20 package slides 1.57 down a long ramp that is inclined at 13.0 ...
physics - A 5.20 package slides 1.57 down a long ramp that is inclined at 13.0 ...
physics - A 5.40 Kg package slides 1.47 meters down a long ramp that is inclined...
physics - a 2.00kg copper plate with an initial temperature of 20.0 degrees ...
Physics/Math - A cold package of hot dogs slides rightward across a frictionless...
physics work and newton - A 2.0 kg object starts from rest from the top of an ...
Physics - A brick of mass 1.0 kg slides down an icy roof inclined at 30.0 ...
For Further Reading
