As shown in figure, two blocks are connected with a light spring. When spring was at its natural length, velocities are given to them as shown in figure. Choose the wrong alternative.
Velocity of center of mass of the system is $3\, m/s$ (towards right)
When spring is maximum compressed velocity of $20\, kg$ block is $3\, m/s$ (towards
right)
When spring is maximum elongated velocity of $10\, kg$ block is $3\, m/s$ (towards
left)
Both $(A)$ and $(C)$
$10\ m$ is the total mass of a cannon that includs all shell. Initial cannon is moving with velocity $10\ m$ is along a horizontal frictionless path. If cannon fires $'n$' shells of mass $m$ in the direction of motion of the cannon one by one with velocity $u$ with respect to ground. (neglect any friction force)
A block $(B)$ is attached to two unstretched springs $\mathrm{S} 1$ and $\mathrm{S} 2$ with spring constants $\mathrm{k}$ and $4 \mathrm{k}$, respectively (see figure $\mathrm{I}$ ). The other ends are attached to identical supports $M1$ and $M2$ not attached to the walls. The springs and supports have negligible mass. There is no friction anywhere. The block $\mathrm{B}$ is displaced towards wall $1$ by a small distance $\mathrm{x}$ (figure $II$) and released. The block returns and moves a maximum distance $\mathrm{y}$ towards wall $2$ . Displacements $\mathrm{x}$ and $\mathrm{y}$ are measured with respect to the equilibrium position of the block $B$. The ratio $\frac{y}{x}$ is Figure: $Image$
A block of mass $m$, lying on a smooth horizontal surface, is attached to a spring (of negligible mass) of spring constant $k$. The other end of the spring is fixed, as shown in the figure. The block is initially at rest in a equilibrium position. If now the block is pulled with a constant force $F$, the maximum speed of the block is
slowing down of neutrons: In a nuclear reactor a neutron of high speed (typically $10^{7}\; m s ^{-1}$ ) must be slowed to $10^{3}\; m s ^{-1}$ so that it can have a high probability of interacting with isotope $^{235} _{92} U$ and causing it to fission. Show that a neutron can lose most of its kinetic energy In an elastic collision with a light nuclel like deuterlum or carbon which has a mass of only a few times the neutron mass. The material making up the light nuclel, usually heavy water $\left( D _{2} O \right)$ or graphite, is called a moderator.
A one kg block moves towards a light spring with a velocity of $8\, m/s$. When the spring is compressed by $3\, m$, its momentum becomes half of the original momentum. Spring constant of the spring is :-