A body dropped from height $‘H’$ reaches the ground with a speed of $1.1 \sqrt {gH}$ . Calculate the work done by air friction? .............. $\mathrm{mgH}$
A body dropped from height $‘H’$ reaches the ground with a speed of $1.1 \sqrt {gH}$ . Calculate the work done by air friction? .............. $\mathrm{mgH}$
- A
$0.395$
- B
$-0.395$
- C
$0.400$
- D
$-0.400$
Similar Questions
An engine is attached to a wagon through a shock absorber of length $1.5\, {m}$. The system with a total mass of $40,000\, {kg}$ is moving with a speed of $72\, {kmh}^{-1}$ when the brakes are applied to bring it to rest. In the process of the system being brought to rest, the spring of the shock absorber gets compressed by $1.0\, {m}$. If $90\, \%$ of energy of the wagon is lost due to friction, the spring constant is $....\, \times 10^{5}\, {N} / {m}$
An engine is attached to a wagon through a shock absorber of length $1.5\, {m}$. The system with a total mass of $40,000\, {kg}$ is moving with a speed of $72\, {kmh}^{-1}$ when the brakes are applied to bring it to rest. In the process of the system being brought to rest, the spring of the shock absorber gets compressed by $1.0\, {m}$. If $90\, \%$ of energy of the wagon is lost due to friction, the spring constant is $....\, \times 10^{5}\, {N} / {m}$
- [JEE MAIN 2021]
A rough inclined plane is placed on car moving with a constant velocity $u$ on horizontal ground. A block of mass $ M$ rests on the inclined plane. Is any work done by force of friction between the block and inclined plane ? Is there then a dissipation of energy ?
A rough inclined plane is placed on car moving with a constant velocity $u$ on horizontal ground. A block of mass $ M$ rests on the inclined plane. Is any work done by force of friction between the block and inclined plane ? Is there then a dissipation of energy ?
The total work done on a particle is equal to the change in its kinetic energy. This is applicable
The total work done on a particle is equal to the change in its kinetic energy. This is applicable
A raindrop of mass $1.00\, g$ falling from a height of $1\,km$ hits the ground with a speed of $50\,m s^{-1}$. Calculate
$(a)$ the loss of $PE$ of the drop
$(b)$ the gain in $KE$ of the drop
$(c)$ Is the gain in $KE$ equal to loss of $PE$ ? If not why ?
Take, $g = 10\, m s^{-2}$.
A raindrop of mass $1.00\, g$ falling from a height of $1\,km$ hits the ground with a speed of $50\,m s^{-1}$. Calculate
$(a)$ the loss of $PE$ of the drop
$(b)$ the gain in $KE$ of the drop
$(c)$ Is the gain in $KE$ equal to loss of $PE$ ? If not why ?
Take, $g = 10\, m s^{-2}$.
Two monkeys with the same mass stand on a branch at height $h$ above the horizontal jungle floor. Monkey $A$ steps off the branch holding the end of an inextensible rope of length $L$ whose other end is tied to another branch at height $H$, lets go at the bottom of the swing, and falls freely to the floor, as shown below. Monkey $B$ steps off and falls straight downward. Then, neglecting air resistance but not the tension in the rope, the total work $W$ done on each monkey and the speed $v$ with which each hits the floor are as follows:
Two monkeys with the same mass stand on a branch at height $h$ above the horizontal jungle floor. Monkey $A$ steps off the branch holding the end of an inextensible rope of length $L$ whose other end is tied to another branch at height $H$, lets go at the bottom of the swing, and falls freely to the floor, as shown below. Monkey $B$ steps off and falls straight downward. Then, neglecting air resistance but not the tension in the rope, the total work $W$ done on each monkey and the speed $v$ with which each hits the floor are as follows: