A target is made of two plates, one of wood and the other of iron. The thickness of the wooden plate is $4\,cm$ and that of iron plate is $2\,cm$. A bullet fired goes through the wood first and then penetrates $1\,cm$ into iron. A similar bullet fired with the same velocity from opposite direction goes through iron first and then penetrates $2\,cm$ into wood. If $a_1$ and $a_2$ be the retardations offered to the bullet by wood and iron plates respectively, then
A target is made of two plates, one of wood and the other of iron. The thickness of the wooden plate is $4\,cm$ and that of iron plate is $2\,cm$. A bullet fired goes through the wood first and then penetrates $1\,cm$ into iron. A similar bullet fired with the same velocity from opposite direction goes through iron first and then penetrates $2\,cm$ into wood. If $a_1$ and $a_2$ be the retardations offered to the bullet by wood and iron plates respectively, then
- A
$a_1=2 a_2$
- B
$a_2=2 a_1$
- C
$a_1=a_2$
- D
Data insufficient
Similar Questions
Refer to the graph in figure. Match the following
Graph
Characteristics
$(A)$
$(i)$ has $v > 0$ and $a < 0$ throughout
$(B)$
$(ii)$ has $x > 0,$ throughout and has a point with $v = 0$ and a point with $a = 0$
$(C)$
$(iii)$ has a point with zero displacement for $t > 0$
$(D)$
$(iv)$ has $v < 0$ and $a > 0$
Refer to the graph in figure. Match the following
| Graph | Characteristics |
| $(A)$ | $(i)$ has $v > 0$ and $a < 0$ throughout |
| $(B)$ | $(ii)$ has $x > 0,$ throughout and has a point with $v = 0$ and a point with $a = 0$ |
| $(C)$ | $(iii)$ has a point with zero displacement for $t > 0$ |
| $(D)$ | $(iv)$ has $v < 0$ and $a > 0$ |
For the acceleration-time $(a-t)$ graph shown in figure, the change in velocity of particle from $t=0$ to $t=6 \,s$ is ........ $m / s$
For the acceleration-time $(a-t)$ graph shown in figure, the change in velocity of particle from $t=0$ to $t=6 \,s$ is ........ $m / s$
$Assertion$ : A body with constant acceleration always moves along a straight line.
$Reason$ : A body with constant acceleration may not speed up.
$Assertion$ : A body with constant acceleration always moves along a straight line.
$Reason$ : A body with constant acceleration may not speed up.
- [AIIMS 1998]
A motorist starting a car from rest accelerates uniformly to a speed of $v\, m/s$ in $9\, seconds$. He maintains this speed for another $50\, seconds$ and then applies the brakes and decelerates uniformly to rest. His deceleration is numberically equal to three times his previous acceleration. Then the time during which the deceleration takes place is ..........$s$ :-
A motorist starting a car from rest accelerates uniformly to a speed of $v\, m/s$ in $9\, seconds$. He maintains this speed for another $50\, seconds$ and then applies the brakes and decelerates uniformly to rest. His deceleration is numberically equal to three times his previous acceleration. Then the time during which the deceleration takes place is ..........$s$ :-
The accompanying graph of position $x$ versus time $t$ represents the motion of a particle. If $p$ and $q$ are both positive constants, the expression that best describes the acceleration $a$ of the particle is
The accompanying graph of position $x$ versus time $t$ represents the motion of a particle. If $p$ and $q$ are both positive constants, the expression that best describes the acceleration $a$ of the particle is
- [KVPY 2013]