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प्रश्न
Is the motion of moon around the earth in circular path an accelerated motion?
उत्तर
Yes, it is an accelerated motion.
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संबंधित प्रश्न
Can there be displacement of an object in the absence of any force acting on it? Think. Discuss this question with your friends and teacher.
Define work.
Define 1 joule of energy.
Give reasons for the following. No work is done if a man is pushing against a wall.
In which of the following cases, is work being done?
(i) A man pushing a wall.
(ii) a coolie standing with a load of 12 kgf on his head.
(iii) A boy climbing up a staircase.
A boy throws a rubber ball vertically upwards. What type of work, positive or negative, is done : by the force applied by the boy?
(a) by the force applied by the boy?
(b) by the gravitational force of earth?
Explain by an example that a body may possess energy even when it is not in motion.
In case of negative work, the angle between the force and displacement is :
Determine the amount of work done when an object is displaced at an angle of 30° with respect to the direction of the applied force.
What is meant by a translational motion? Give one example.
No work is done by a man moving on a horizontal road while carrying a box on his head. Explain.
A boy pulls a box up to 10 m with a force of 5 kgf. Calculate the work done by him.
Fill in the boxe to show the corresponding energy transformation.
Is power a scalar or a vector quantity?
What should be the characteristic of a source of energy?
A force is applied on a body of mass 20 kg moving with a velocity of 40 ms−1. The body attains a velocity of 50 ms−1 in 2 seconds. Calculate the work done by the body.
Mention whether work is done or not in the following activity.
| S. No | Activity | Work done or not done |
| 1. | Pushing the door | |
| 2. | Holding a doll | |
| 3. | Sitting in a bus | |
| 4. | Pushing a wall | |
| 5. | Digging soil |
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
A wind-mill is lifting water from a well.
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
A green plant is carrying out photosynthesis.
