MCQ
If momentum is increased by $20 \%$, then K.E. increases by
- ✓$44 \%$
- B$55 \%$
- C$66 \%$
- D$77 \%$
✓
Answer
Correct option: A.
$44 \%$
(a)
$E=\frac{P^2}{2 m} $. If $m$ is constant then
$E \propto P^2 \Rightarrow \frac{E_2}{E_1}=\left(\frac{P_2}{P_1}\right)^2=\left(\frac{1.2P}{P}\right)^2=1.44 $
$\Rightarrow E_2=1.44 E_1=E_1+0.44 E_1 $
$E_2=E_1+44 \% \text { of }E_1$
i.e.the kinetic energy will increase by $44 \%$
$E=\frac{P^2}{2 m} $. If $m$ is constant then
$E \propto P^2 \Rightarrow \frac{E_2}{E_1}=\left(\frac{P_2}{P_1}\right)^2=\left(\frac{1.2P}{P}\right)^2=1.44 $
$\Rightarrow E_2=1.44 E_1=E_1+0.44 E_1 $
$E_2=E_1+44 \% \text { of }E_1$
i.e.the kinetic energy will increase by $44 \%$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
The Rutherford $\alpha$-particle experiment shows that most of the $\alpha$ particles pass through almost unscattered while some are scattered through large angles. What information does it give about the structure of the atom
→Pressure gradient has the same dimension as that of
The vector diagram of current and voltage for a circuit is as shown. The components of the circuit will be
If the wavelength of light is $4000\ \mathring A$, then the number of waves in 1 mm length will be
→liquid oxygen remains suspended between two pole faces of a magnet because it is
If an electron revolves in the path of a circle of radius of $0.5 \times 10$ $\mathrm{m}$ at frequency of $5 \times 10^{-} \mathrm{cycles} / \mathrm{s}$ the electric current in the circle is (Charge of an electron $=1.6 \times 10^{-19} C$ )
→A spring is stretched by $0.20 m$, when a mass of $0.50 kg$ is suspended. When a mass of $0.25 kg$ is suspended, then its period of oscillation will be $\left(g=10 m / s ^2\right)$
→In Milikan's oil drop experiment, a charged drop falls with terminal velocity $V$. If an electric field $E$ is applied in vertically upward direction then it starts moving in upward direction with terminal velocity $2 \mathrm{~V}$. If magnitude of electric field is decreased to $\frac{E}{2}$, then terminal velocity will become
→An $L C R$ series circuit with a resistance of $100 ohm$ is connected to an ac source of $200 V($ r.m.s. $)$ and angular frequency $300 rad / s$. When only the capacitor is removed, the current lags behind the voltage by $60^{\circ}$. When only the inductor is removed the current leads the voltage by $60^{\circ}$. The average power dissipated is
→The ratio of densities of nitrogen and oxygen is $14:16.$ The temperature at which the speed of sound in nitrogen will be same at that in oxygen at $55 {}^\circ\mathrm{C}$ is
→