Question
A block rests on a horizontal frictionless surface. A string is attached to the block, and is pulled with a force of 60.0 N at an angle θ above the horizontal. After the block is pulled through a distance of 2.00 m, its speed is 2.70 m/s, and 43.0 J of work has been done on it.
A)What is the angle θ?
B)Calculate the mass of the block.
A)What is the angle θ?
B)Calculate the mass of the block.
Answers
A. Work = F*cosA * d = 43 J.
60*cosA * 2.0 = 43
120*cosA = 43
cosA = 0.35833
A = 69o
B. a = (V^2-Vo^2)/2d
a = (2.7^2-0)/4 = 1.82 m/s^2.
F*cos69 = m*a
60*cos69 = m*1.82
m = 60*cos69/1.82 = 11.80 kg.
60*cosA * 2.0 = 43
120*cosA = 43
cosA = 0.35833
A = 69o
B. a = (V^2-Vo^2)/2d
a = (2.7^2-0)/4 = 1.82 m/s^2.
F*cos69 = m*a
60*cos69 = m*1.82
m = 60*cos69/1.82 = 11.80 kg.