Chapter 14.2, Problem 19R

To determine

The force needed to lift the object.

Answer to Problem 19R

The force needed to lift the object is $420\text{N}$ .

Explanation of Solution

Given info:

Weight of the object, $W=21000\text{N}$

Area of the piston, $a=0.060{\text{m}}^2$

Area of the platform, $A=3{\text{m}}^2$

Formula Used:

Write the expression to calculate the force needed to lift the object.

  $F=\frac{W\cdot a}{A}$

Calculation:

Substitute all the values in the above expression.

  $\begin{array}{c}F=\frac{\left(21000\text{N}\right)\left(0.060{\text{m}}^2\right)}{3{\text{m}}^2}\\ =420\text{N}\end{array}$

Conclusion:

Thus, the force needed to lift the object is $420\text{N}$ .