Download Aptitude Crack
img not found img not found

Applied Mechanics - Engineering

Q1:

If the angle between the applied force and the direction of motion of a body, is between 90° and 180°, the work done, is called

A virtual work

B imaginary work

C zero work

D negative work.

ANS:D - negative work.

Work, W = PCosθ.

And we know Cos is (-ve) in 2nd quadrant i.e. (θ= 90° to 180°)
W= - PCosθ ( work is negative ).

Or,

Simply as θ is between 90° to 180°, the force acting & the direction of motion is opposite to each other, that's why the work will be negative.