Question

A force of 120 n is applied on a toy car at an angle 60° with the horizontal direction, displaces it through a distance of 2.5m along the horizontal floor. Calculate the work done by force. Is the work positive or negative.given cos =60°0.5

Answer 1

Answer on Question #74172, Physics / Atomic and Nuclear Physics

Question. A force of $120\,N$ is applied on a toy car at an angle $60{}^{\circ}$ with the horizontal direction, displaces it through a distance of $2.5\,m$ along the horizontal floor. Calculate the work done by force. Is the work positive or negative. Given $\cos 60{}^{\circ} = 0.5$.

Given. $F = 120\,N; r = 2.5\,m; \alpha = 60{}^{\circ}$.

Find. $A - ?$

Solution.

By definition

$$A = \left(\vec{F} \cdot \vec{r}\right).$$

So

$$A = \left(\vec{F} \cdot \vec{r}\right) = F \cdot r \cdot \cos \alpha = 120 \cdot 2.5 \cdot \cos 60{}^{\circ} = 150\,J.$$

Answer. $A = 150\,J$; the work is positive.

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