MCQ
A body is projected with velocity $u$ making an angle $\alpha$ with the horizontal. Its velocity when it is perpendicular to the initial velocity vector $u$ is
- A$u \,tan\alpha$
- ✓$u\, cot\alpha$
- C$u\, cosec\alpha$
- D$u \,sec\alpha$
✓
Answer
Correct option: B.
$u\, cot\alpha$
b
$'O' = u\cos \alpha $
$'O' = u\cos \alpha $
$'P' = v\sin \alpha $
$v\sin \alpha = u\cos \alpha $
$\Rightarrow \,v = u\cot \alpha $
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
A train starts from rest from a station with acceleration $0.2 \,m / s ^2$ on a straight track and then comes to rest after attaining maximum speed on another station due to retardation $0.4 \,m / s ^2$. If total time spent is half an hour, then distance between two stations is [Neglect length of train]
→A solid sphere, disc and solid cylinder all of the same mass and made of the same material are allowed to roll down (from rest) on the inclined plane, then ....
A body of mass $m$ is thrown upwards at an angle $\theta$ with the horizontal with velocity $v$. While rising up the velocity of the mass after $ t$ seconds will be
→An object of mass $2 \,kg$ at rest at origin starts moving under the action of a force $\vec{F}=\left(3 t^2 \hat{i}+4 \hat{j}\right) N$ The velocity of the object at $t=2 \,s$ will be ............. $m / s$
→Given below are two statements:
→Statement $I:$ Acceleration due to earth's gravity decreases as you go 'up' or 'down' from earth's surface.
Statement $II:$ Acceleration due to earth's gravity is same at a height ' $h$ ' and depth ' $d$ ' from earth's surface, if $h = d$.
In the light of above statements, choose the most appropriate answer form the options given below
Two soap bubbles coalesce to form a single bubble. If $V$ is the subsequent change in volume of contained air and $S$ change in total surface area, $T$ is the surface tension and $P$ atmospheric pressure, then which of the following relation is correct?
→The given diagram shows a detector placed between a transmitter of sound waves and a metal plate. At three adjacent points, $ R, S$ and $T$ , the meter shows zero intensity. Which of the following is the frequency of the emitted wave ... $Hz$ ? (Take the velocity of sound as $ = 300\ m/s$ )
→Two particles of mass $m$ each are tied at the ends of a light string of length $2a$ . The whole system is kept on a frictionless horizontal surface with the string held tight so that each mass is at a distance $'a'$ from the centre $P$ (as shown in the figure). Now, the mid-point of the string is pulled vertically upwards with a small but constant force $F$ . As a result, the particles move towards each other on the surface. The magnitude of acceleration, when the separation between them becomes $2x$ , is
→A quarter horse power motor runs at a speed of $ 600 r.p.m.$ Assuming $40\%$ efficiency the work done by the motor in one rotation will be
→If $r$ represents the radius of the orbit of a satellite of mass $m$ moving around a planet of mass $ M$, the velocity of the satellite is given by
→