Question

1.Potential energy cannot be expressed in ——- 

 a)J               

 b) Nm               

 c) Ns           

 d) Ws

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Answer 1

Potential Energy cannot be expressed in c) Ns.

But why ?

• First of all, potential energy is a type of mechanical energy possessed by a body by the virtue of its position with respect to the reference frame.

• So, potential energy will have dimensions and units similar to that of 1) work done or 2) product of power and time

• Now, SI unit of work is expressed either as Joule (J) or Watt-Second (Ws).

• It can also be expressed as Newton-metre (Nm) [i.e. force × Displacement].

$\star$ So, option c) Newton-Second (Ns) is incorrect ❌