Question

a work of 1000J is done on a body in 4s, such that displacement of 20m is caused . calculate( a )Force. ( b ) power​

Answer 1

ANSWER:

• Force = 50 N

• Power = 250 watt

GIVEN:

• Work done = 1000 J.

• Time = 4 s.

• Displacement = 20 m.

TO FIND:

• a) Force.

• b) Work.

FORMULAE USED:

FORCE = WORK DONE÷DISPLACEMENT

POWER = WORK DONE ÷ TIME

EXPLANATION:

a) FORCE:

Force = ( 1000 J ) ÷ 20 m

Force = 100 / 2

Force = 50 N

b) POWER:

Power = ( 1000 J ) ÷ 4 s

Power = 250 Watt

Hence the Power = 250 Watt and Force = 50 N

ADDITIONAL POINTS:

• Other unit of power = J / s

• 1 J / s = 1 watt

• Dimensional formula of Power = [ M L² T⁻³ ]

• Dimensional formula of Force = [ M L T⁻² ]

Answer 2

Question:–

a work of 1000J is done on a body in 4s, such that displacement of 20m is caused . calculate( a )Force. ( b ) power.

Answer:–

a)50N

b)250w

Solution:–

(a) Force F = w/s = 1000J/20 = 50N

(b) P = w/t = 1000J/4s = 250JS-1 = 250w.