Conservation of linear momentum
0.1×20=(0.1+1.9)×v
v=1ms−1
Using work energy theorem
Wg=Δk
2×g×1=k−21×2×12
∴k=21J
A block of mass 1.9kg is at rest at the edge of a table, of height 1 m. A bullet of mass 0.1kg collides with the block and sticks to it. If the velocity of the bullet is 20ms−1 in the horizontal direction just before the collision then the kinetic energy just before the combined system strikes the floor, is [Take g=10ms−2. Assume there is no rotational motion and loss of energy after the collision is negligible.]
Held on 3 Sept 2020 · Verified 6 Jul 2026.
21J
20J
19J
23J
Sign in to track your attempts and accuracy.
Sign in to keep a private note on this question. Nothing you write is ever public.
Net gravitational force at the center of a square is found to be $F_{1}$ when four particles having mass $M, 2 M, 3 M$ and $4 M$ are placed at the four corners of the square as shown in figure and it is $F_{2}$ when the positions of $3 M$ and $4 M$ are interchanged. The ratio $\frac{F_{1}}{F_{2}}$ is $\frac{\alpha}{\sqrt{5}}$. The value of $\alpha$ is $\_\_\_\_$. 
A particle of mass 2 kg is projected vertically upward with a speed of 30 m/s. The maximum height reached by the particle is (g = 10 m/s²):
Two projectiles are projected with the same initial velocities at the $15^\circ$ and $30^\circ$ with respect to the horizontal. The ratio of their ranges is $1:x$. The value of $x$ is:
In an experiment the values of two spring constants were measured as $k_{1}=(10 \pm 0.2) \mathrm{N} / \mathrm{m}$ and $k_{2}=(20 \pm 0.3) \mathrm{N} / \mathrm{m}$. If these springs are connected in parallel, then the percentage error in equivalent spring constant is :
The surface tension of a soap solution is $3.5 \times 10^{-2}$ N/m. The work required to increase the radius of a soap bubble from $1$ cm to $2$ cm is $\alpha \times 10^{-6}$ J. The value of $\alpha$ is _____. ($\pi = 22/7$)
Work through every JEE Main Mechanics PYQ, year by year.