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
The torque of force $\vec F = - 2\hat i + 2\hat j + 3\hat k$ acting on a point $\vec r = \hat i - 2\hat j + \hat k$ about origin will be
→What is the maximum value of the force $F$ such that the block shown in the arrangement does not move ....... $N$
→In the figure shown a mass $1\ kg$ is connected to a string of mass per unit length $1.2\ gm/m$ . Length of string is $1\ m$ and its other end is connected to the top of a ceiling which is accelerating up with an acceleration $2\ m/s^2$ . A transverse pulse is produced at the lowest point of string. Time taken by pulse to reach the top of string is .... $s$
→Planetary system in the solar system describes
Figure represents two simple harmonic motions. The parameter which has different values in the two motions is:
- Amplitude.
- Frequency.
- Phase.
- Maximum velocity.
The velocity at the maximum height of a projectile is half of its initial velocity $u$. Its range on the horizontal plane is
→An ice box used for keeping eatable cold has a total wall area of $1\;metr{e^2}$ and a wall thickness of $5.0cm$. The thermal conductivity of the ice box is $K = 0.01\;joule/metre{ - ^o}C$. It is filled with ice at ${0^o}C$ along with eatables on a day when the temperature is $30°C$ . The latent heat of fusion of ice is $334 \times {10^3}joules/kg$. The amount of ice melted in one day is ........ $gms$ ($1day = 86,400\;\sec onds$)
→Let Fpp' Fpn and Fnn fill denote the magnitudes of the nuclear force by a proton on a proton, by a proton on a neutron and by a neutron on a neutron respectively. When the separation is 1fm:
- Fpp > Fpn = Fnn
- Fpp = Fpn = Fnn
- Fpp > Fpn > Fnn
- Fpp < Fpn = Fnn
The $P.E.$ of a certain spring when stretched from natural length through a distance $0.3\, m$ is $10\, J$. The amount of work in joule that must be done on this spring to stretch it through an additional distance $0.15\, m$ will be ................ $\mathrm{J}$
→Two particles start simultaneously from the same point and move along two straight lines, one with uniform velocity $v$ and other with a uniform acceleration $a$. If $\alpha$ is the angle between the lines of motion of two particles, then the least value of relative velocity will be at time given by
→