How much work is required to push a crate 60.9 cm across a floor if you apply a constant horizontal force of 35.0 N? Express your response in J to three significant digits as ab.c J. The values for a, b and c are:



Answer :

Answer:

[tex]23.1\; {\rm J}[/tex]. ([tex]\text{$\texttt{2}$, $\texttt{3}$, and $\texttt{1}$}[/tex].)

Explanation:

The work that a force exerted on an object is equal the product of:

  • the force, and
  • the displacement of the object in the direction of the force.

In this question, assuming that the object is moving in the same direction as the external [tex]35.0\; {\rm N}[/tex] force (horizontal.) The displacement in the direction of this force would be [tex]60.9\; {\rm cm}[/tex] as given.

The question is asking for a result measured in joules. Note that [tex]1\; {\rm J} = 1\; {\rm N\cdot m}[/tex]. While the force is already measured in the standard unit of newtons, make sure the displacement of the object is also in the appropriate unit, meters:

[tex]\displaystyle 60.9\; {\rm cm} \times \frac{1\; {\rm m}}{100\; {\rm cm}} = 0.609\; {\rm m}[/tex].

Hence, the work that this force exerted on the object would be:
[tex]\begin{aligned}(\text{work}) &= (\text{force})\, (\text{displacement}) \\ &= (0.609\; {\rm m})\, (35.0\; {\rm N}) \\ &\approx 21.3\; {\rm N\cdot m} \\ &= 21.3\; {\rm J}\end{aligned}[/tex].

(Rounded to three significant figures.)