List of top Physics Questions on Relative Velocity

Consider an equilateral prism (refractive index \( \sqrt{2} \)). A ray of light is incident on its one surface at a certain angle \( i \). If the emergent ray is found to graze along the other surface, then the angle of refraction at the incident surface is close to
A spaceship moves with a velocity of 5000 m/s. What is the relativistic factor \( \gamma \) for the spaceship? (Given that \( c = 3 \times 10^8 \, \text{m/s} \))
Two cities X and Y are connected by a regular bus service with a bus leaving in either direction every T min. A girl is driving scooty with a speed of 60 km/h in the direction X to Y. She notices that a bus goes past her every 30 minutes in the direction of her motion, and every 10 minutes in the opposite direction. Choose the correct option for the period T of the bus service and the speed (assumed constant) of the buses.
A river is flowing from west to east direction with speed of \(9\) km/hr. If a boat capable of moving at a maximum speed of \(27\) km/hr in still water, crosses the river in half a minute, while moving with maximum speed at an angle of \(150^\circ\) to direction of river flow, then the width of the river is:
Rain, pouring down at an angle \( \alpha \) with the vertical, has a constant speed of 10 m/s. A woman runs against the rain with a speed of 8 m/s and sees that the rain makes an angle \( \beta \) with the vertical. The relation between \( \alpha \) and \( \beta \) is given by:
When two objects are moving along a straight line in the same direction, the distance between them increases by 6 m in one second. If the objects move with their constant speed towards each other, the distance decreases by 8 m in one second. Then the speed of the objects are:

A body of mass \( (5 \pm 0.5) \, \text{kg} \) is moving with a velocity of \( (20 \pm 0.4) \, \text{m/s} \). Its kinetic energy will be:

Two trains 'A' and 'B' of length \('l'\) and \('4l'\) are travelling into a tunnel of length 'L' in parallel tracks from opposite directions with velocities 108 km/h and 72 km/h, respectively. If train 'A' takes 35s less time than train 'B' to cross the tunnel then. length 'L' of tunnel is:
(Given L = 60 \(l\))
A bullet of 10 g leaves the barrel of gun with a velocity of 600 m/s. If the barrel of gun is 50 cm long and mass of gun is 3 kg, then value of impulse supplied to the gun will be :
A planet having mass \(9M_e\) and radius \(4R_e\), where \(M_e\) and \(R_e\) are mass and radius of earth respectively, has escape velocity in km/s given by: (Given escape velocity on earth \(V_e= 11.2 × 10^3 m/s\))
A fish rising vertically upward with a uniform velocity of 8 ms-1, observes that a bird is diving vertically downward towards the fish with the velocity of 12 ms-1. If the refractive index of water is \(\frac{4}{3}\) , then the actual velocity of the diving bird to pick the fish, will be _______ ms-1

A particle of mass 𝑚 is moving in the xy-plane such that its velocity at a point (x, y) is given as \(\overrightarrow{v}=a(y\^{x}+2x\^{y})\) where 𝛼 is a non-zero constant. What is the force F acting on the particle?

A uniform metallic wire carries a current $2 A$, when $34 V$ battery is connected across it The mass of uniform metallic wire is $892 \times 10^{-3} kg$, density is $892 \times 10^3 kg / m ^3$ and resistivity is $17 \times 10^{-8} \Omega- m$ The length of wire is :

A solid sphere of mass $1 \,kg$ rolls without slipping on a plane surface Its kinetic energy is $7 \times 10^{-3} J$. The speed of the centre of mass of the sphere is ___$cm s ^{-1}$.

A particle moves along x-axis following the relation x = 4(t-2)+a(1-2)², where x is the distance travelled in time t. In that case, which of the following statement(s) is/are true?
Consider a light ray travelling in air is incident into a medium of refractive index √2n The incident angle is twice that of refracting angle. Then, the angle of incidence will be:
A heavy nucleus at rest breaks into two fragments which fly off with velocities in the ratio 3 : 1. The ratio of radii of the fragments is

A swimmer wants to cross a river from point A to point B. Line AB makes an angle of 30$^\circ$ with the flow of river. Magnitude of velocity of the swimmer is same as that of the river. The angle $\theta$ with the line AB should be ________ $^\circ$, so that the swimmer reaches point B. 

 

At a metro station, a girl walks up a stationary escalator in 20 sec. If she remains stationary on the escalator, then the escalator take her up in 30 sec. The time taken by her to walk up on the moving escalator will be
The speed of a swimmer in still water is \(20 m/s\). The speed of river water is \(10 m/s\) and is flowing due east. If he is standing on the south bank and wishes to cross the river along the shortest path, the angle at which he should make his strokes w.r.t. north is given by:
Consider a ship traveling due east along the equator with velocity $v_0$. If southeastern wind blows at an angle of $' \phi '$ to the equator with velocity $'v'$, the wind velocity relative to the ship $v'$ and the angle between the equator and the wind direction in the reference frame fixed to the ship are
Two particle are moving in opposite direction with speed v1 and v2. What may be their velocity if relative velocity is 6 m/sec
A rain drop of radius 0.3 mm has a terminal velocity in air 1 ms-1. The viscosity of air is \(18×10^{-5}\) poise. Find the viscous force on the rain drops.
Water flows through a horizontal pipe of variable cross-section at the rate of 20 L min-1. What will be the velocity of water at a, point where diameter is 4 cm?
A current is flowing through the wire of diameter \(d\) having drift velocity of electron \(v_d\) in it. What will be new drift velocity when diameter of wire is made \(\frac d4\) ?