Start Free Mock LoginAlready registered? Login here

Physics - W.E.P. Question with Solution | TestHub

PhysicsW.E.P.MiscellaneousMedium2 minQB

PhysicsMediumnumerical

A block moving horizontally on a smooth surface with a speed of $40 {m s}^{- 1}$ splits into two equal parts. If one of the parts moves at $60 {m s}^{- 1}$ in the same direction, then the fractional change in the kinetic energy will be $x : 4$ where $x =$ ________.

Answer:

1.00

Solution:

$2 m \times 40 = 60 \times m + m v$
$V = 20 m / s$
Now $Δ K E = K E_{f} - K E_{i} = \frac{1}{2} m \times (20)^{2} + \frac{1}{2} m \times (60)^{2} - \frac{1}{2} 2 m \times (40)^{2}$
$Δ K E = \frac{1}{2} m (800) \Rightarrow K E_{i} = \frac{1}{2} 2 m \times (40)^{2} = \frac{1}{2} m \times 3200$
Fractional change $= \frac{Δ K E}{K E_{i}} = \frac{1}{4}$

Stream:JEESubject:PhysicsTopic:W.E.P.Subtopic:Miscellaneous

⏱ 2mℹ️ Source: QB

Doubts & Discussion

Loading discussions...