Advertisements
Advertisements
Question
A body of mass 0.2 kg falls from a height of 10 m to a height of 6 m above the ground. Find the loss in potential energy taking place in the body. [g = 10ms−2]
Advertisements
Solution
Given, Mass = 0.2 kg
Height, h = 10 m to 6 m
Loss in Potential Energy = mg (h1 − h2)
= 0.2 × 10 (10 − 6) = 8 J
APPEARS IN
RELATED QUESTIONS
A hydroelectric power station takes its water from a lake whose water level is 50 m above the turbine. Assuming an overall efficiency of 40%, calculate the mass of water which must flow through the turbine each second to produce power output of 1 MW. (Take g = 10 m s−2).
The following are some of the energy transformations.
A. Electrical to light
B. Work to heat
C. Chemical to light
D. Electrical to sound
E. Mechanical to electrical
Identify the energy transformation that takes place in the following by inserting the corresponding letter in the shape provided.
(i) A candle flame
(ii) A torch is lighted
(iii) A microphone is used in a meeting
(iv) A cycle dynamo
(v) A piece of metal is being filed
Show that the quantity 2K/v2 has the unit of mass, where K is the kinetic energy of the body.
What do you understand by the potential energy of the body?
What kind of energy is possessed in a situation when?
A horse running along a level road
What is dissipation of energy?
State the energy changes which take place when:
A toy car spring is wound and car is made to run on level floor.
Give one example when:
Mechanical energy changes to electric energy.
A ball of mass 200 g falls from a height of 5 m. What will be its kinetic energy when it just reaches the ground? (g = 9.8 m s−2)
Match the pairs.
| Group 'A' | Group 'B' | ||
| (1) | Rolling object | (a) | Heat energy |
| (2) | Food | (b) | Atomic energy |
| (3) | Stretched bow | (c) | Kinetic energy |
| (4) | Sunlight | (d) | Potential energy |
| (5) | Uranium |
(e)
|
Chemical energy
|
