A contestant in a winter games event pushes a 59.0 kg block of ice across a froz

ID: 1627503 • Letter: A

Question

A contestant in a winter games event pushes a 59.0 kg block of ice across a frozen lake as shown in the figure.

The coefficient of static friction is 0.1 and the coefficient of kinetic friction is 0.03.

(a)

Calculate the minimum force F (in N) he must exert to get the block moving.

_______N

(b)

What is its acceleration (in m/s2) once it starts to move, if that force is maintained?

_______m/s2

Question 2

A contestant in a winter games event pushes a 59.0 kg block of ice across a frozen lake with a rope over his shoulder as shown in the figure.

The coefficient of static friction is 0.1 and the coefficient of kinetic friction is 0.03.

(a)

Calculate the minimum force F (in N) he must exert to get the block moving.

_____N

(b)

What is its acceleration (in m/s2) once it starts to move, if that force is maintained?

______m/s2

Question 1

(a) F*cos (25 deg) = [0.1*{(59*9.81) +F*sin (25 deg}] or,

F*[cos (25 deg) - (0.1*sin (25 deg))] = (5.9*9.81) or,

F = [(5.9*9.81)/{cos (25 deg) - (0.1*sin (25 deg)}]

F = 67 N

(b) a = (1/59)*[(67*cos (25 deg) - {0.03*{(59*9.81) + 67*sin (25 deg)}]

a = 1.34 m/s^2

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