A person pulls a body on a horizontal surface by applying a force of 5.0 N at an angle of 30° with the horizontal.Find the workdone by this force in displacing the body through 2.0 m?
5√3 J
6√2 J
7√3 J
4√3 J
The energy required to raise a given volume of water from a well can be:
Mega watts
Mega newton
Mega joules
Kilo watts
The work done is :
A vector quantity
A scalar quantity
Always positive
Always negative
A radio set of 60 watts runs for 50 hours.How many 'units ' (kWh) of electricaly energy are consumed ?
6 kWh
4 kWh
3 kWh
30 kWh
By what factor does the kinetic energy of a particle increase if the velocity is increased by a factor of three?
6
7
8
9
Which of the following graphs closely represents the kinetic energy (k) of a freely falling body and its height (h) above the ground?
Two bodies of equal weight are kept at heights of h and 1.5 h respectively.The ratio of their P.E. is
3 : 2
2 : 3
1 : 1
1 : 2
What are the conditions that would satisfy to reveal work is done?
A force should act on an object
The object must be displaced
Both 'a' and ;'b'
a only
An iron sphere of mass 30kg has the same diameter as an aluminium sphere of mass 10.5 kg. The spheres are dropped simultaneously from a cliff. When they are 10m above from the ground,they have the same :
Acceleration
Momentum
Potential energy
K.E.
What is the velocity of a body of mass 100 g having a K.E. of 20 J?
2 ms-1
20 ms-1
40 ms-1
400 m/s
