Physics Test 11...

The sum & differences of two perpendicular vectors of equal magnitudes are

An aeroplane is moving on a circular path with a speed of 250 kmph. The change in velocity (in kmph) in half revolution is

If the sum of two unit vectors is also a unit vector, then the magnitude of their difference is

A person aims a gun at a bird from a point, at a horizontal distance of 100 m.If gun can impart a speed of 500m/s to the bullet,at what height above the bird must he aim his gun in order to hit it? (g = 10 ms^-2)

The hight y and distance x along the horizontal plane of a projectile on a certain planet (With no surrounding atmosphere) are given as y=y=8t-5t² mtr. and x = 6t metres, where t is in seconds. The velocity with which the projectile is projected is 

A helicopter flying at 20 m/s horizontally drops a rescue bag. Ignoring air resistance & taking g = 10ms^-2, the displacement of the bag 5 seconds after the drop began is nearly

When the angular velocity of a uniformly rotating body has increased thrice, the resultant of forces applied to it increase by 60 N. Find the acceleration of the body in the two cases. The mass of the body, m = 3kg

In case of uniform circular motion which of the following physical quantities do not remain constant?

A parachutist of weight W strikes the ground with his legs fixed and comes to rest with an upward acceleration of magnitude 3g . force exerted on him by ground during landing is

An unloaded car moving with velocity u on a road can be stopped in a distance s. If passengers add 40% to its weight and braking force remains the same, the stopping distance at velocity u is now