Work-energy Theorem

Question

Net work on a 4 kg body is 80 J from rest. Final speed?

RankGuru · Accepted Answer

1. **Work-Energy Theorem**: The net work done on an object is equal to its change in kinetic energy ($W_{net} = \Delta K$).
2. **Constraint**: Since it starts from rest, $K_{initial} = 0$.
3. **Formula**: $W_{net} = \frac{1}{2} m v^2$.
4. **Solve for v**:
   - $v^2 = \frac{2 W}{m}$
   - $v = \sqrt{\frac{2 	imes 80}{4}} = \sqrt{\frac{160}{4}} = \sqrt{40}$.
5. **Calculation**: $\sqrt{40} \approx 6.3245$ m/s.
6. **Result**: Final speed is **$6.32$ m/s**.

Work-energy Theorem

Select the correct option:

🔒 Solution Hidden from View

More work, energy and power Practice Questions

A net force performs 150 J of work on a 3 kg trolley that starts from rest on a frictionless rail. W...

A particle of mass 0.5 kg starts from rest and acquires a velocity of 10 m/s under the action of a c...

Net work done on an object equals change in:

Net work done on an object equals change in:

About This Question

Solution