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A football player at practice pushes a 60 kg blocking sled across the field at a constant speed. The coefficient of kinetic friction between the grass and the sled is 0.30.

How much force must he apply to the sled?

A. 18 N

B. 60 N

C. 180 N

D. 600 N

Respuesta :

Answer:

C. 180 N

Explanation:

[tex]m[/tex] = mass of the blocking sled = 60 kg

[tex]\mu[/tex] = Coefficient of kinetic friction = 0.30

[tex]f[/tex] = kinetic frictional force acting on the sled

kinetic frictional force acting on the sled is given as

[tex]f = \mu mg = (0.30) (60) (10) = 180 N[/tex]

[tex]F[/tex] =Force applied

For the sled to move at constant speed, the applied force must be same as the frictional force

[tex]F = f\\F = 180 N[/tex]