Q31 of 43 Page 85

A reckless drunk is playing with a gun in an airplane that is going directly east at 500 kmhr–1. The drunk shoots the gun straight up at the ceiling of the plane. The bullet leaves the gun at a speed of 1000 kmhr–1. Relative to an observer on earth what angle does the bullet make with the vertical?

We first define our axis

Upward is along + y direction of axis


Eastward is along + x direction of axis


Velocity of a aeroplane =


Velocity of a Bullet =


A person on the earth will see the bullet having a resultant velocity and angle θ with the vertical (y axis)



θ = angle with the vertical (y axis)




More from this chapter

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29

A body moves 6 m north, 8 m east and 10m vertically upwards. What is its resultant displacement from the initial position?

 30

A body revolves with a constant speed v in a circular path of radius r. The magnitude of its average acceleration during motion between 2 points in diametrically opposite direction is?

 32

From the top of a tower 19.6m high a ball is thrown horizontally. If the line joining the point of projection to the point where it hits ground makes an angle of 45° with the horizontal then initial velocity of ball is:

a) 9.8 ms–1


b) 4.9 ms–1


c) 14.7 ms–1


d) 2.8 ms–1

 33

Prove: For an elevation which exceed or fall short of 45° by equal amounts the ranges are equal.