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## Previous Year Papers

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Class 10 Class 12

A ball is thrown vertically downwards from a height of 20m with an initial velocity vo, It collides with the ground, loses 50% of its energy in collision and rebounds to the same height. The initial velocity vo is,
(Take g = 10 ms-2)

• 14 ms-1

• 20 ms-1

• 28 ms-1

• 10 ms-1

B.

20 ms-1

Suppose a ball rebounds with speed v,

Suppose a ball rebounds with speed v,

7781 Views

What are different units of energy?

The different units of energy are :

(i) Joule
(ii) Erg
(iii) eV
(iv) KWh
(v) Calorie.

804 Views

Define the unit joule.

Work done is said to be one joule if one newton of  force displaces the body through a distance of one meter in the direction of applied  force .
799 Views

Define watt.

Power is said to be one watt if one joule of work is done in one second.
860 Views

What is watt?

SI unit of power is Watt.
773 Views

Is work a scalar or a vector quantity?

Work is dot product of two vectors. i.e. .

And dot product is a scalar quantity. Therefore, work is a scalar quantity.
1450 Views