$A$ boy throws a ball in the air at $60^{\circ}$ to the horizontal,along a road with a speed of $10 \, m/s$. Another boy sitting in a passing car observes the ball. Sketch the motion of the ball as observed by the boy in the car,if the car has a speed of $18 \, km/h$. Give an explanation to support your diagram.
(N/A) The boy throws the ball at an angle of $60^{\circ}$ with a speed of $10 \, m/s$.
The horizontal component of the ball's velocity is $v_x = v \cos \theta = 10 \cos 60^{\circ} = 10 \times 0.5 = 5 \, m/s$.
The speed of the car is $18 \, km/h = 18 \times \frac{5}{18} = 5 \, m/s$.
Since the horizontal component of the ball's velocity $(5 \, m/s)$ is equal to the speed of the car $(5 \, m/s)$,the relative horizontal velocity of the ball with respect to the car is $v_{rel,x} = 5 - 5 = 0 \, m/s$.
Therefore,the boy in the car will observe the ball moving only in the vertical direction,which appears as a straight vertical line path.
The horizontal component of the ball's velocity is $v_x = v \cos \theta = 10 \cos 60^{\circ} = 10 \times 0.5 = 5 \, m/s$.
The speed of the car is $18 \, km/h = 18 \times \frac{5}{18} = 5 \, m/s$.
Since the horizontal component of the ball's velocity $(5 \, m/s)$ is equal to the speed of the car $(5 \, m/s)$,the relative horizontal velocity of the ball with respect to the car is $v_{rel,x} = 5 - 5 = 0 \, m/s$.
Therefore,the boy in the car will observe the ball moving only in the vertical direction,which appears as a straight vertical line path.
Explore More
Similar Questions
On a long horizontal belt,a child runs to and fro with a speed of $9\,km/h$ (with respect to the belt) between his father and mother located $50\,m$ apart on the moving belt. The belt moves with a speed of $4\,km/h.$ For an observer on the platform,the speed of the child in the direction of motion of the belt is.........$km/h$.
Easy
View Solution$STATEMENT-1$ For an observer looking out through the window of a fast-moving train,the nearby objects appear to move in the opposite direction to the train,while the distant objects appear to be stationary.
$STATEMENT-2$ If the observer and the object are moving at velocities $\vec{V}_1$ and $\vec{V}_2$ respectively with reference to a laboratory frame,the velocity of the object with respect to the observer is $\vec{V}_2 - \vec{V}_1$.
$STATEMENT-2$ If the observer and the object are moving at velocities $\vec{V}_1$ and $\vec{V}_2$ respectively with reference to a laboratory frame,the velocity of the object with respect to the observer is $\vec{V}_2 - \vec{V}_1$.
DifficultIIT 2008
View SolutionAn aeroplane is to go along a straight line from $A$ to $B$,and back again. The relative speed with respect to wind is $V$. The wind blows perpendicular to the line $AB$ with speed $v$. The distance between $A$ and $B$ is $\ell$. The total time for the round trip is:
Medium
View SolutionTwo boys are standing at points $A$ and $B$ on the ground where distance $AB = a$. The boy at point $B$ starts running perpendicular to line $AB$ with velocity $V_1$. The boy at point $A$ starts running simultaneously with velocity $V$ and catches the other boy in time $t$. The value of $t$ is
DifficultMHT CET 2026
View SolutionOn a two-lane road,car $A$ is travelling with a speed of $36 \; km/h$. Two cars $B$ and $C$ approach car $A$ in opposite directions with a speed of $54 \; km/h$ each. At a certain instant,when the distance $AB = AC = 1 \; km$,car $B$ decides to overtake car $A$ before car $C$ does. What minimum acceleration (in $m/s^2$) of car $B$ is required to avoid an accident?
Medium
View SolutionVedclass Products
For Students
Vedclass Test Series
Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.
Start Free TrialFor Teachers
Exam Paper Generator
Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.
Try FreeFor Institutes
Online Exam Module
Live online exams with unlimited students, 360° analytics & white-label branding.
See Demo