Question

What is the Work done in pulling a body of mass of 80kg through 100 meters, given that coefficient of friction is 0•7 and g=10m/s

Answer 1

Answer:

Work done = 56000J

Explanation:

Friction force

= N x coefficient of friction

= 800 x 0.7

= 560 N/m

(N = Mg = 80 x 10 = 800N)

Total work done = Force of friction x Displacement

= 560 x 100

= 56000J

= 56kJ

Answer 2

$\Huge{\underline{\underline{\mathfrak{Answer \colon}}}}$

From the Question,

• Mass of the block,m = 80 Kg

• Displacement,s = 100 m

• Coefficient of Friction,u = 0.7

To find

Work Done by the frictional force.

Firstly,we need to find the fictional force

$\huge{\boxed{\boxed{\sf{f = \mu mg}}}}$

Substituting the values,we get :

→ f = (0.7)(80)(10)

→ f = (7)(80)

→ f = 560 N

Now,

$\huge{\boxed{\boxed{\tt{W = f.s}}}}$

→ W = (560)(100)

→ W = 56,000

→ W = 56 KJ

Thus,the work done by the frictional force is 56 KJ