Physics Motion in Plane

The angular acceleration of a body, moving along the circumference of a circle, is:

A bullet is fired from a gun at the speed of 280 m/s in the direction ${30}^{?}$ above the horizontal. The maximum height attained by the bullet is $\left(\mathrm{g}=9.8{\mathrm{m}\mathrm{s}}^{-2},\mathrm{s}\mathrm{i}\mathrm{n}?{30}^{?}=0.5\right)$

A small block slides down on a smooth inclined plane, starting from rest at time $t=0$ . Let $S_n$ be the distance travelled by the block in the interval $t=n-1$ to $t=n$ . Then, the ratio $\frac{S_n}{S_{n+1}}$  is:

Two transparent media A and B are separated by a plane boundary. The speed of light in those media are $1.5*{10}^8\mathrm{m}/\mathrm{s}$ and $2.0*{10}^8\mathrm{m}/\mathrm{s}$ , respectively. The critical angle for a ray of light for these two media is

A horizontal bridge is built across a river. A student standing on the bridge throws a small ball vertically upwards with a velocity $4{\mathrm{m}\mathrm{s}}^{-1}$ . The ball strikes the water surface after $4\mathrm{s}$ . The height of bridge above water surface is (Take $\mathrm{g}=$ $10{\mathrm{m}\mathrm{s}}^{-2}$  ):

A bullet is fired from a gun at the speed of $280\mathrm{m}/\mathrm{s}$ in the direction ${30}^{\circ }$ above the horizontal. The maximum height attained by the bullet is

$\left(\mathrm{g}=9.8{\mathrm{m}\mathrm{s}}^{-2},\mathrm{s}\mathrm{i}\mathrm{n}?{30}^{?}=0.5\right)$

A person is swimming with a speed of 10m/s at an angle of 120° with the flow and reaches to a point directly opposite on the other side of the river. The speed of the flow is 'x' m/s. The value of 'x' to the nearest integer is-----------.

The velocity of a particle is v = v₀ + gt + Ft². Its position is x = 0 at t = 0; then its displacement after time (t = 1) is:

A helicopter rises from rest on the ground vertically upwards with a constant acceleration g. A food packet is dropped from the helicopter when it is at a height h. The time taken by the packet to reach the ground is close to [ g is the acceleration due to gravity]:

A balloon is moving up in air vertically above a point A on the ground. When it is at a height h₁, a girl standing at a distance d (point B) from A (see figure) sees it at the angle 45° with respect to the vertical. When the balloon climbs up a future height h₂, it is seen at the angle 60° with respect to the vertical if the girl moves further by a distance 2.464 d (point C). Then the height h₂ is (given tan 30° = 0.5774) :