A bomb is projected upwards. At topmost point it explodes in three identical fragments. First fragment comes to ground in $10\  sec$. and others in $20\  sec$ each. Then the height reached by the original bomb is.........$m$

  • A

    $800$

  • B

    $1600$

  • C

    $1250$

  • D

    $1500$

Similar Questions

A projectile is fired at a speed of $100\, m/sec$ at an angle of $37^o$ above the horizontal. At the highest point, the projectile breaks into two parts of mass ratio $1:3$ , the smaller coming to rest. Then the distance of heavier part from the launching point is ............... $\mathrm{m}$

A ball is projected from top of a tower with a velocity of $5\,\, m/s$ at an angle of $53^o$ to horizontal. Its speed when it is at a height of $0.45 \,\,m$ from the point of projection is  ........ $m/s$

A bullet weighing $10 \,g$ and moving with a velocity $300 \,m / s$ strikes a $5 \,kg$ block of ice and drop dead. The ice block is kept on smooth surface. The speed of the block after the collision is ........ $cm / s$

A person trying to lose weight (dieter) lifts a $10\; kg$ mass, one thousand times, to a hetght of $0.5\; m$ each time. Assume that the potential energy lost each time she lowers the mass is dissipated.

$(a)$ How much work does she do against the gravitational force?

$(b)$ Fat supplies $3.8 \times 10^{7} \;J$ of energy per kilogram which is converted to mechanical energy with a $20 \%$ efficiency rate. How much fat will the dieter use up?

In an elastic collision of two billiard balls, which of the following quantities remain conserved during the short time of collision of the balls ? (i.e. when they are in contact)

$(a)$ Kinetic energy.

$(b)$ Total linear momentum.

Give reason for your answer in each case.