How much work would be done if a 50 kg block was pulled horizantally at a 30 degree angle to the horizantal for 10 meters.
a) With zero friction
b) With -100N friction
Wb = mg = 50kg * 9.8N/kg = 490N. = Weight of block.
Fb = 490N @ odeg.
Fh=490sin(0) = 0 = Hor. force of block
Fv = 490cos(0) = 490N. = Force perpendicular to surface = Normal.
a. Fap*cos30 - Fh - Ff = 0,
Fap*cos30 - 0 - 0 = 0,
Fap*cos30 = 0,
Fap = 0 = Force applied.
Work = Fd = 0 * 10 = 0.
b. Fap*cos30 - 0 - 100 = 0,
Fap*cos30 = 100,
Fap = 100 / cos30 = 115.5N. = Force applied.
Work = Fd = 115.5cos30 * 10 = 1000J.