Question

a)How much work is done by a force of 80 N in moving an object through a distance of 5 m in the direction of the force?

b)300 J of work is done on a body to cause a displacement of 12 m.How much force is applied on the body?

c)100 J of work is done by a force of 10 N in moving an object in the direction of the force.Calculate the displacement of the body.

d)Calculate the work done in lifting 300 kg of water from a well through a height of 20 m
[g=9.8 m/s2]

e)Calculate the vertical height through which a body of mass 10 kg is lifted when 1470 J of work is done in lifting it.[g=9.8 m/s2]

f)Calculate the power of an electric bulb which does an electric work of 800 J in 20 s.

g)Calculate the potential energy possessed by a body of mass 15 kg at a height of 20 m.
[g=9.8 m/s2]

h)The kinetic energy of a moving body of mass 10 kg is 8000 J.Calculate its velocity.

i)A body of mass 8 Kg falls from a height of 20 m.If g=9.8 m/s2 What is the potential energy possessed by the body at that height?What is its kinetic energy just before touching the ground.

j)Name the energy change i) in a room heater ii)charging of a mobile battery iii)burning of cooking gas iv)Photosynthesis.

k)State the two conditions under which work done is zero giving one example for each.

Answer 1

Answer:

A. 16

B. ?

C. ?

D ?

Explanation:

Answer 2

Answer:

Step-by-step explanation:

Step-by-step explanation:

( 31 + 28 + 31 + 30 + 31 + 30 + 31 + 15 ) = 227 days = (32 weeks + 3 days) = 3 odd days. Total number of odd days = (0 + 1 + 1 + 3) = 5 odd days. Hence, as the number of odd days = 5 , given day is Friday.