Which is the correct expression for potential energy of an object?
mgh
1/2 mv2
2mgh
mgh2
The energy required to raise a given volume of water from a well can be:
Mega watts
Mega newton
Mega joules
Kilo watts
The force applied and displacement of the body are inclined at 900with each other, calculate the work done ?
Infinite
Maximum
Zero
Unity
Two girls, each of weight 400 N climb up a rope through a height of 8m. We name one of the girls as A and the other as B. Girl A takes 20s while B takes 50s to accomplish this task. What is the power expended by each girl ?
64 W girl A and 160 W for girl B
128 W girl A and 320 W for girl B
160 W for girl A and 64 W for girl B
320 W for girl A and 128 W for girl B
An object of mass 12 kg is at a certain height above the ground. If the potential energy of the object is 480 J,find the height at which the object is with respect to the ground? Given g = 10 ms-2
4 m
4 mm
40 m
400 m
1 hp is equal to
0.746 kW
7.46 kW
74.6 kW
746 kW
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
A boy of mass 50 kg runs up staircase of 45 steps in 9 s. If the height of each step is 15 cm, find his power. Take g = 10ms-1
400 W
275 W
375 W
575 W
A ball of mass 200 g falls from a height 0f 5 m. What is its K.E when it just reaches the ground ?
9.6 J
98 J
980 J
9600 J
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