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`)

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

Ten small planes are flying at a speed of 150km/h in total darkness in an air space that is 20xx20xx1.5 km^3 in volume. You are in one of the planes, flying at random within this space with no way of knowing where the other planes are. On the average about how long a time will elapse between near collision with your plane. Assume for this rough computation that a safety region around the plane can be approximated by a sphere of radius 10m.

An aeroplane in which the distance between the tips of wings is 50 m is flying horizontal with a speed of 360km//hr over a place where the verticle components of earth magnetic field is 2.0xx10^(-4)webr//m^(2) . The potential different between the tips of wings would be

A body of mass 0.40 kg moving initially with a constant speed of 10 m s^-1 to the north is subject to a constant force of 8.0 N directed towards the south for 30 s. Take the instant the force is applied to be t = 0, the position of the body at that time to be x = 0, and predict its position at t = -5 s, 25 s, 100 s.

A jet plane is travelling towards west at a speed of 1800 km//h . What is the voltage difference developed between the ends of the wing 25 m long, If the Earth’s magnetic field at the location has a magnitude of 5 xx 10^-4T and the dip angle is 30^@ .

A metre gauge train is runing due north with a constant speed of 90 km h^-1 on a horizontal track. If the vertical component of earth's magnetic ield is 3xx10^-5 W b m^-2 , calculate the e.m.f. induced across the axle of the train of length 1.25 cm.

To stimulate car accidents auto manufacturers study the collisions of moving cars with mounted springs of different spring constants. Consider a typical simulation with a car of mass 1000 kg moving with a speed 18 km/h on a smooth road and colliding with a horizontally mounted spring of a spring constant 6.25 10^3N/m. what is the maximum compression of the spring?

A fighter plane flying horizontally at an altitude of 1.5 km with speed 720 km//h passes directly overhead an anti-aircraft gun. At what angle from the vertical should the gun be fired for the shell with muzzle speed 600 m s^-1 to hit the plane ? At what minimum altitude should the pilot fly the plane to avoid being hit ? (Take g = 10 ms^2 ).

A trolley of mass 200 kg moves with a uniform speed of 36 km//h on a frictionless track. A child of mass 20 kg runs on the trolley from one end to the other (10 m away) with a speed of 4 m s^-1 relative to the trolley in a direction opposite to the its motion, and jumps out of the trolley. What is the final speed of the trolley ? How much has the trolley moved from the time the child begins to run ?