Work

Q.

Does the work done in moving a body depend on how fast or how slow the body is moved?

Q.

What is transferred when work is done?

Q.

What is energy?

Q.

Give one word for the following:

The product of magnitude of force and the distance moved by the object in the direction of force.

Q.

1 joule = ___ erg.

Q.

If there is a definite force and a definite displacement of the object, does it mean that work is definitely done by the force?

Q.

When is one joule of work said to be done?

Q.

A pair of bullocks exerts a force of $140N$ on a plough. The field being ploughed is $15m$ long. How much work is done in ploughing the length of the field?

Q.

A force of $4N$ acts through a distance of $11m$ in the direction of the force. The work done is

1. $10J$

2. $11J$

3. $15J$

4. $44J$

Q. When the material $P$ mined from the earth is heated strongly in an insufficient supply of air, if produces a solid fuel $Q$ which consists mainly of carbon. When another material $R$ obtained from trees is heated in an insufficient supply of air, it produces another solid fuel $S$ which also consists mainly of carbon. Name $P,Q,R$ and $S$.

Q.

What is the SI unit of work.

Q.

Work is said to be done, when

1. force acts upon a body, but the body does not move.

2. the force acts upon a body and moves it, in the direction of force

3. force acts upon a body, but the body does not move in the direction of force.

4. none of these

Q.

When a work is said to be done?

Q.

Define SI unit of work.

Q.

When do we say that work is done? Give two examples.

Q.

Mechanically work done is equal to (symbols have their usual meanings)

1. $W=F/d$

2. $W=Fd$

3. $W=F+d$

4. $W=F-d$

Q. Four men lift a $250kg$ box to a height of $1m$ and hold it without raising and lowering it. Is there any work being done while holding? Why do they get tired while holding it? $(g=10m{s}^{-2})$

Q.

A mass of $10kg$ is at a point $A$ on a table. It is moved to a point $B$. If the line joining $A$ and $B$ is horizontal, what is the work done on the object by the gravitational force? Explain your answer.

Q.

$1joule$of work is said to be done when: