Question

A boy does a work of 1000J in dragging a sack of rice through a distance of 20m. what is the magnitude of force applied by the boy?

Answer 1

Explanation:

Provided that:

• Work done = 1000 J
• Displacement = 20 m

To determine:

• Force

Solution:

• Force = 50 Newton

Using concept:

• Work done formula

Using formula:

• Work done = Fs

Where, F denotes force and s denotes displacement.

Required solution:

»»» Work done = Fs

»»» 1000 = F × 20

»»» 1000/20 = F

»»» 100/2 = F

»»» F = 50 m

»»» Force = 50 metre

• Henceforth, solved!

Verification:

»»» Work done = Fs

»»» 1000 = 50 × 20

»»» 1000 = 1000

»»» LHS = RHS

• Henceforth, proved! $\:$

Answer 2

$\frak {Given} = \begin{cases} &\sf{Work \: done = 1000 J} \\\\\\\\\\ &\sf{Displacement = 20 m}\end{cases}$

                     _____________

To find:-        

• The magnitude of force applied by the boy.

Solution:-          

Here, we have a work of 1000J in dragging a sack of rice through a distance of 20m.  

So to find out the magnitude of force applied by the boy we will use the work done formula.  

• The formula of work done is Fs.

                 ____________

Applying the formula of work done,

$\qquad\tt{:\implies\:Work\:done\:=\:Fs}$

Where,

• Force = F  
• displacement = s

$\qquad\tt{:\implies\:1000\:=\:F\:\times\:20}$

$\qquad\tt{:\implies\:F\:=\:\dfrac{1000}{20}}$

$\qquad\tt{:\implies\:F\:=\:\dfrac{100}{2}}$

$\qquad\tt{:\implies\:F\:=\:50\:m}$

Thus, the magnitude of force applied by the boy is 50 m.