In a test experiment on a model aeroplane in a wind tunnel, the flow speeds on the upper and lower surfaces of the wing are `70 m s^-1`and `63 m s^-1` respectively. What is the lift on the wing if its area is `2.5 m^2` ? Take the density of air to be `1.3 kg m^-3`

Two narrow bores of diameters 3.0 mm and 6.0 mm are joined together to form a U-tube open at both ends. If the U-tube contains water, what is the difference in its levels in the two limbs of the tube ? Surface tension of water at the temperature of the experiment is 7.3xx 10^-2 N m^-1 '. Take the angle of contact to be zero and density of water to be 1.0xx 10^3 kg m^- 3 ( g = 9.8 m s^-2 ) .

What is the density of water at a depth where pressure is 80.0 atm, given that its density at the surface is 1.03 xx 103 kg m^-3 ?

A plane is in level flight at constant speed and each of its two wings has an area of 25 m^2 . If the speed of the air is 180 km//h over the lower wing and 234 km//h over the upper wing surface, determine the plane’s mass. (Take air density to be 1 kg m^-3 )

The dimensions of a cubois are in the ratio of 1:2:3 and its total surface area is 198m^2 . Find the dimensions.

Light enters from air to diamond having refractive index 2.4. what is the speed of light in diamond ? Given speed of light in vacuum =3xx10^8 m s^-1 .

A 120 m long train is moving west at a speed of 10 m s^-1 .A small bird flying cast at a speed of 5 ms^-1 crosses the train.What is the time taken by the bird to cross the train?

The acceleration due to gravity on the surface of moon is 1.7 m s^-2 . What isthe time period of a simple pendulum on the surface of moon if itstime period on the surface of earth is 3.5 s? (gon the surface of earth is 9.8 m s6-2 )

A particle executing circular motion of radius 5 m and linear speed of 3 ms^-1 which is increasing at the rate of 2 m s^-2 .What is the acceleration of the particle?

What are the two angles of projection of a projectile with velocity 30 m s^-1 , so that the horizontal range is 45 m.Take g=10 m s^-2 .

A boy is running towards a plane mirror with a speed of 2 m s^(-1) .With what speed the image of the boy approach him?