A person pushes a 16.0-kg shopping cart at a constant velocity for a distance of 16.0 m. she pushes in a direction 30.0° below the horizontal. a 54.0-n frictional force opposes the motion of the cart. (a) what is the magnitude of the force that the shopper exerts? n (b) determine the work done by the pushing force. j (c) determine the work done by the frictional force. j (d) determine the work done by the gravitational force. j

Question

Physics

Jerry

18 May, 10:06

A person pushes a 16.0-kg shopping cart at a constant velocity for a distance of 16.0 m. she pushes in a direction 30.0° below the horizontal. a 54.0-n frictional force opposes the motion of the cart. (a) what is the magnitude of the force that the shopper exerts? n (b) determine the work done by the pushing force. j (c) determine the work done by the frictional force. j (d) determine the work done by the gravitational force. j

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Answers (1)

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Chanel Cruz · Answer 1

Let:

P - pushing force,

t - angle below horizontal,

F - friction force.

Resolving horizontally:

P cos (t) = F

(a)

P = F / cos (t)

= 54 / cos (30.0)

= 62.35

(b)

Work done by P

= P cos (t) * 16.0

= F * 16.0

= 54.0 * 16.0

= 864J

(c)

Work done by F

= - F * 16.0

= - 54 * 16.0

= - 864 J.

(d)

As there is no motion vertically, the work done by the gravitational force is 0.