Problem 7: A contender in a winter sports contest pulls a 49 kg cube of ice in t
ID: 1580671 • Letter: P
Question
Problem 7: A contender in a winter sports contest pulls a 49 kg cube of ice in the positive horizontal direction with a cable over his shoulders over' a frozen lake as shown in the figure. Assume the coefficients of static and kinetic friction are .-0 l and ,-0 03. 125 Ctheexpertta.com Part (a) Calculate the minimum force F he must exert to get the cube sliding in newtons. Numerie A numeric value is expected and not an expression Fmie Part (b) What is its acceleration in m/s once it starts to move, if that force is maintained? Numerie :A numeric value is expected and not an expression.Explanation / Answer
a) minimum Force required is Fmin = maximum static frictional Force = mu_s*N
Net Force along horizontal direction is
F*cos(25) = fs_max = mu_s*N = mu_s*[(F*sin(25)+(m*g)]
F*cos(25) = 0.1*((F*sin(25))+(49*9.8))
F = 55.57 N
b) Fnet = m*a
F*cos(25) - mu_k*[(F*sin(25)+(m*g)] = m*a
(55.57*cos(25)) - (0.03*((55.57*sin(25))+(49*9.8))) = 49*a
accelaration is a = 0.72 m/s^2