List of top Physics Questions on Speed and velocity

A person observes two moving trains, ‘A’ reaching the station and ‘B’ leaving the station with equal speed of 30 m/s. If both trains emit sounds with frequency 300 Hz, (Speed of sound: 330 m/s) approximate difference of frequencies heard by the person will be:

For particle P revolving round the centre O with radius of circular path r and angular velocity ω, as shown in below figure, the projection of OP on the x-axis at time t is

Given below are two statements:
Statement I: Area under velocity- time graph gives the distance travelled by the body in a given time.
Statement II: Area under acceleration-time graph is equal to the change in velocity- in the given time.
In the light of given statements, choose the correct answer from the options given below.

Figure below shows a liquid being pushed out of the tube by a piston having area of cross section 2.0 cm². The area of cross section at the oulet is 10 mm². If the piston is pushed at a speed of 4 cm s^-1, the speed of outgoing fluid is ______ cm s^-1.

The speed of a wave produced in water is given by v=\(λ^ag^bρ^c\). Where λ,g and ρ are wavelength of wave, acceleration due to gravity and density of water respectively. The values of a, b and c respectively, are:

Match List I with List II List I List II A. Spring constant I. (T-1) B. Angular speed II. (MT-2) C. Angular momentum III. (ML2) D. Moment of Inertia IV. (ML2T-1)

	List I		List II
A	Spring constant	I	(T-1)
B	Angular speed	II	(MT-2)
C	Angular momentum	III	(ML2)
D	Moment of Inertia	IV	(ML2T-1)

Choose the correct answer from the options given below:

A person travels x distance with velocity v₁ and then x distance with velocity v₂ in the same direction. The average velocity of the person is v, then the relation between v, v₁ and v₂ will be

A particle is thrown vertically upward with initial velocity of 150 m/s. Find the ratio of its speed at t = 3 seconds and t = 5 seconds. is \(\frac{x+1}{x}\) the value of x is___. (take g = 10 m/s2)

An ice cube has a bubble inside. When viewed from one side the apparent distance of the bubble is 12 cm. when viewed from the opposite side, the apparent distance of the bubble is observed as 4 cm. If the side of the ice cube is 24 cm, the refractive index of the ice cube is

A current of 2 A flows through a wire of crosssectional area 25.0 mm2 . The number of free electrons in a cubic meter are 2.0 x 10²⁸ . The drift velocity of the electrons is _____ x 10^-6 ms^-1 (Given, charge on electron = 1.6 x 10^-19C)

To maintain a speed of 80 km/h by a bus of mass 500 kg on a plane rough road for 4 km distance, the work done by the engine of the bus will be ____KJ. [The coefficient of friction between tyre of bus and road is 0.04].

Rain is falling vertically with a speed of 40 $m s^{-1}$. Wind starts blowing with a speed of 16 $m s^{-1}$ in the west to east direction. How should a person, who is standing, hold his umbrella to avoid getting wet?

Electrons are accelerated by 344 volts and reflected from the crystal. The first reflection maximum occurs when glancing angle is 30°. What will be the value of interplanar spacing of the crystal? [Given h=6.62×10^-34 Js, m_e = 9.1x10^-31 kg]

What will be drift velocity \(v_d\) of the free electron in a copper wire whose cross sectional area is A = 1.00 mm² when the wire carries a current of 1.0 A. Assume that each copper atom contributes 1 electron to the electron gas. (Given density of copper = 8.94x10³ kg/m³, atomic mass of copper = 63.5 u, 1 u = 1.66x10^-27 kg)

If the stream function equation y=3x²-y², what is the magnitude of velocity at point (2.2)?

Consider an inertial frame S' moving at a speed \(\frac{c}{3}\) away from another inertial frame S along the common x-axis, where c is the speed of light. As observed from S', a particle is moving with speed \(\frac{c}{3}\) in the y' direction as shown in the figure. The speed of the particle as seen from S will be

A bullet of mass 10 g moving horizontally with a speed of 500 m/s passes through a block of wood of mass 1 kg, initially at rest on a frictionless surface. The bullet comes out of the block with a speed of 200 m/s. What is the final speed of the block?

Let \(\overrightarrow r_P(t)=3t\hat i+4t²\hat j\) and \(\overrightarrow r_Q(t)=4t^2\hat i+3t\hat j\) represent the positions of particles P and respectively as function of time t. The relative speed of the two particles at the instant t = 1 sec will be [consider \(\overrightarrow r_P(t)\) and \(\overrightarrow r_Q(t)\) are in metres and t is in seconds]

Five molecules of an ideal gas have velocities 2, 3, 4, 4 and 5 m/s. If their average velocity is \(\bar v\) and their RMS velocity is \(V_{rms}\) then

A thin uniform rod of length L and mass M is swinging freely about a horizontal axis passing through its end. Its maximum angular speed is ω. Its centre of mass rises to a maximum height of

The velocity \(v\) of a particle as a function of time t is given by \(v(t) = v_0 (1 – e^{–αt})\). The dimension of \(v_0/α\) is

An artificial satellite is moving in a circular orbit around the earth with a speed equal to half the magnitude of the escape velocity from the earth's surface. The height of the satellite above the earth's surface is [R = Radius of the earth]

A girl standing on road holds her umbrella at 45° with the vertical to keep the rain away. If she starts running without umbrella with a speed of \(15\sqrt2\) \(kmh^{–1}\), the rain drops hit herhead vertically. The speed of rain drops with respect to the moving girl is

A car covers a distance at speed of \(60\text{ km h}^{-1}\). It returns and comes back to the original point moving at a speed of \(V\). If the average speed for the round trip is \(48\text{ km h}^{-1}\), then the magnitude of \(V\) is