MEDIUM
9th CBSE
IMPORTANT
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Write the relation between power, energy and time.

Important Questions on Work and Energy

MEDIUM
9th CBSE
IMPORTANT
All In One SCIENCE CBSE Class IX>Chapter 11 - Work and Energy>CHAPTER EXERCISE>Q 19
When water is flowing through a pipe, then its velocity changes by 5% find the change in percentage, in the power water.
MEDIUM
9th CBSE
IMPORTANT
All In One SCIENCE CBSE Class IX>Chapter 11 - Work and Energy>CHAPTER EXERCISE>Q 20
A boy of mass 50 kg runs up a staircase of 50 steps in 10 s. if the height of each step is 15 cm, then find the his power. (take,g=10ms-2)
MEDIUM
9th CBSE
IMPORTANT
All In One SCIENCE CBSE Class IX>Chapter 11 - Work and Energy>CHAPTER EXERCISE>Q 21
A geyser of 2.5 kw is used for 6 h daily. Calculate the cost of electricity consumed in 10 days. Electricity rate per unit ₹ 4.
MEDIUM
9th CBSE
IMPORTANT
All In One SCIENCE CBSE Class IX>Chapter 11 - Work and Energy>CHAPTER EXERCISE>Q 22
What do you understand by the term “transformation of energy?” explain with an example.
MEDIUM
9th CBSE
IMPORTANT
All In One SCIENCE CBSE Class IX>Chapter 11 - Work and Energy>CHAPTER EXERCISE>Q 22

Explain the transformation of energy in the following case.

A ball thrown upwards

MEDIUM
9th CBSE
IMPORTANT
All In One SCIENCE CBSE Class IX>Chapter 11 - Work and Energy>CHAPTER EXERCISE>Q 22
Explain the transformation of energy in the following case.
A stone dropped from the roof of a building 
 
MEDIUM
9th CBSE
IMPORTANT
All In One SCIENCE CBSE Class IX>Chapter 11 - Work and Energy>CHAPTER EXERCISE>Q 23
A ball thrown vertically upwards returns to the thrower. How do the kinetic energy (KE) and potential energy (PE) of the ball change?
MEDIUM
9th CBSE
IMPORTANT
All In One SCIENCE CBSE Class IX>Chapter 11 - Work and Energy>CHAPTER EXERCISE>Q 23
Calculate the power of pump which lifts 100 kg of water to a water tank placed at a height of 20 m in 10 s.(take,g=10ms-2)