Work done by a constant force

Constant force

“If the magnitude and direction of a force remains same, then thee force is said to be a constant force”.

Explanation:

Consider a constant force ’F’ which acts on a body at an angle’ Ө’ and displaces it from position ‘A’ to ‘B’ through a displacement ‘d’.

Work:

“The product of the magnitude and the component of the force in the direction of the displacement is called work”.

W =F . d

= (F Cos Ө) =Fd Cos Ө

Graphical Method:

Consider a graph between force and distance. The distance is normally taken along x-axis and the force along y-axis. Since the force is constant so the graph will be a horizontal straight line.

If the constant force (Newton) and the displacement d (meter) are in the same direction, then the work done is fd (joule).

Also the shaded area is also Fd. Hence the area under a force displacement curve is equal to the work done by the force. If the force F is not in the direction of displacement, the graph is plotted between F Cos Ө and d.

•SCALAR QUANTITY:

Work is the dot product of two vectors, hence it is a scalar quantiy

.•IF Ө< 90֯ :

Work is done and is said to be positive work.

•IF Ө= 90֯ :

No work is done.

IF Ө> 90֯ :

The work done is said to be negative.

Unit:

SI unit of work is N m known as joule (j).

Mathematically:

1j = 1N × 1m

Joule:

“If a force of 1 newton acts on a body and displaces it through a distance of 1m in its direction, then the work done will be 1 joule”.

Dimensions:

The dimension of work are.

[work] = [Fd] = [ ML² T-² ] View more on psalmfresh.blogspot.com for more educating and tricks article Thank you