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## Homework Statement

A worker pushed a 27 kg block 7.8 m along a level floor at constant speed with a force directed 32° below the horizontal.

(a) If the coefficient of kinetic friction is 0.20, how much work was done by the worker's force?

(b) What was the increase in thermal energy of the block-floor system?

## Homework Equations

Probably could use Fnet = ma

Work = F*distance

Friction is [tex]\mu[/tex]N

## The Attempt at a Solution

(a) If the coefficient of kinetic friction is 0.20, how much work was done by the worker's force?

I drew a FBD and found N = (Weight)+(Force of worker in Y-axis(Fwy)) and in the x direction (Fwx - Friction force) = ma

Fwx - [tex]\mu[/tex][(Weight)+(Force of worker in Y-axis(Fwy))] = ma

would a = 0m/s^2 in the x-direction since the object is moving at a constant speed. . .if yes then. . .

Fwx = [tex]\mu[/tex][(Weight)+(Force of worker in Y-axis(Fwy))]

but then I get lost again. . . .