iran-konkur 2014 Q163

iran-konkur · Other · konkur-riazi_1393 Not Maths
163- In the figure below, an appropriate force $F$ parallel to the inclined surface is applied to a body of mass $m = 20\ \text{kg}$ so that the body moves down the incline at constant speed. How much work does force $F$ do in the time that the body travels $2$ meters down the incline?
$$\left(g = 10\ \frac{\text{m}}{\text{s}^2},\ \sin 37^\circ = 0.6\right)$$
[Figure: Mass $m$ on an inclined plane at $37^\circ$ with $\mu_k = 0.25$, force $F$ directed up the incline]
  • [(1)] $-260$ (2) $-160$
  • [(3)] $+160$ (4) $+260$
\textbf{163-} In the figure below, an appropriate force $F$ parallel to the inclined surface is applied to a body of mass $m = 20\ \text{kg}$ so that the body moves down the incline at constant speed. How much work does force $F$ do in the time that the body travels $2$ meters down the incline?

$$\left(g = 10\ \frac{\text{m}}{\text{s}^2},\ \sin 37^\circ = 0.6\right)$$

\textit{[Figure: Mass $m$ on an inclined plane at $37^\circ$ with $\mu_k = 0.25$, force $F$ directed up the incline]}

\begin{itemize}
\item[(1)] $-260$ \hfill (2) $-160$
\item[(3)] $+160$ \hfill (4) $+260$
\end{itemize}