Question

work done by a forc on a moving object is 100 j. it was travelling at a speed o 2m/s. find the new speed of the object if the mass of object is 2kg. pls answer asap
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Answer 1

Given:

• Work done is 100 Joules
• Initial speed = 2 m/s
• Mass = 2 kg

To find:

• Final speed ?

Calculation:

In this type of questions, always apply WORK-ENERGY THEOREM :

• The work done by a force is equal to the change in kinetic energy of the object.

$W = \Delta KE$

$\implies W = \dfrac{1}{2} m {v}^{2} - \dfrac{1}{2} m {u}^{2}$

$\implies 100= \dfrac{1}{2} m ({v}^{2} - {u}^{2} )$

$\implies 100= \dfrac{1}{2} (2) \{{v}^{2} - {(2)}^{2} \}$

$\implies 100={v}^{2} - 4$

$\implies {v}^{2} = 104$

$\implies v = 10.19 \: m {s }^{ - 1}$

So, final velocity of object is 10.19 m/s