# Train $A$ and train $B$ are running on parallel tracks in the opposite directions with speeds of $36 \mathrm{~km} /$ hour and 72 $\mathrm{km} /$ hour, respectively. A person is walking in train $A$ in the direction opposite to its motion with a speed of $1.8$$\mathrm{km} / hour. Speed \left(\right. in \left.\mathrm{ms}^{-1}\right) of this person as observed from train B will be close to : (take the distance between the tracks as negligible) Question: Train A and train B are running on parallel tracks in the opposite directions with speeds of 36 \mathrm{~km} / hour and 72 \mathrm{km} / hour, respectively. A person is walking in train A in the direction opposite to its motion with a speed of 1.8$$\mathrm{km} /$ hour. Speed $\left(\right.$ in $\left.\mathrm{ms}^{-1}\right)$ of this person as observed from train $B$ will be close to : (take the distance between the tracks as negligible)

1. $29.5 \mathrm{~ms}^{-1}$

2. $28.5 \mathrm{~ms}^{-1}$

3. $31.5 \mathrm{~ms}^{-1 \mathrm{q}}$

4. $30.5 \mathrm{~ms}^{-1}$

JEE Main Previous Year Single Correct Question of JEE Main from Physics Motion in a Straight Line chapter.

JEE Main Previous Year 2 Sep. 2020 (I)

Correct Option: 1

Solution:

### Related Questions

• A particle is moving with speed $v=b \sqrt{x}$ along positive $x$-axis. Calculate the speed of the particle at time $t=\tau$ (assume that the particle is at origin at $\mathrm{t}=0$ ).

View Solution

• All the graphs below are intended to represent the same motion. One of them does it incorrectly. Pick it up.

View Solution

• A car covers the first half of the distance between two places at $40 \mathrm{~km} / \mathrm{h}$ and other half at $60 \mathrm{~km} / \mathrm{h}$. The average speed of the car is

View Solution

• The velocity of a particle is $v=v_{0}+g t+f t^{2}$. If its position is $x=0$ at $t=0$, then its displacement after unit time $(t=$

1) is

View Solution

• A particle located at $x=0$ at time $t=0$, starts moving along with the positive $x$-direction with a velocity ‘ $v$ ‘ that varies as $v=\alpha \sqrt{x}$. The displacement of the particle varies with time as

View Solution

• The velocity $(v)$ and time $(t)$ graph of a body in a straight line motion is shown in the figure. The point $S$ is at $4.333$ seconds. The total distance covered by the body in $6 \mathrm{~s}$ is:

View Solution

• A bullet of mass $20 \mathrm{~g}$ has an initial speed of $1 \mathrm{~ms}^{-1}$, just before it starts penetrating a mud wall of thickness $20 \mathrm{~cm}$. If the wall offers a mean resistance of $2.5 \times 10^{-2} \mathrm{~N}$, the speed of the bullet after emerging from the other side of the wall is close to :

View Solution

• The position of a particle as a function of time $t$, is given by $x(t)=a t+b t^{2}-c t^{3}$ where, $a, b$ and $c$ are constants. When the particle attains zero acceleration, then its velocity will be:

View Solution

• A particle starts from origin $\mathrm{O}$ from rest and moves with a uniform acceleration along the positive $x$-axis. Identify all figures that correctly represents the motion qualitatively ( $a=$ acceleration, $v=$ velocity,$x=$ displacement $t=$ time $)$

View Solution

• A particle starts from the origin at time $\mathrm{t}=0$ and moves along the positive $x$-axis. The graph of velocity with respect to time is shown in figure. What is the position of the particle at time $\mathrm{t}=5 \mathrm{~s}$ ?

View Solution

error: Content is protected !!
Download App