Ex 4.3, 6
If the work done by a body on application of a constant force is directly proportional to the distance travelled by the body, express this in the form of an equation in two variables and draw the graph of the same by taking the constant force as 5 units.
Let the distance travelled by body be x
and the work done by the body be y
Given that work done is directly proportional to distance travelled by body
So, we write equation as
y = kx
here k is a constant force.
Given constant force = 5 units
i.e. k = 5.
So, our equation becomes y = 5x
We need to draw graph
Putting x = 0 ,
y = 5(0)
y = 0
So, (0,0) is a solution of the equation
Putting x = 1 ,
y = 5(1)
y = 5
So, (1,5) is a solution of the equation
Plotting points
Ex 4.3, 6
Also read from the graph the work done when the distance travelled by the body is
(i) 2 units
Here x is distance travelled,
& y is work done
y = 5x
When Distance = 2,
x = 2,
So, y = 5(2) = 10
Work done = 10 units
Ex 4.3, 6
Also read from the graph the work done when the distance travelled by the body is
(ii) 0 units
Here x is distance travelled,
& y is work done
y = 5x
When Distance = 0,
x = 0,
So, y = 5(0) = 0
Work done = 0 units

Made by

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths and Science at Teachoo.