Question

if a ball is projected horizontally with speed 30m/s and height 1000 m under gravity. velocity of projectile 4 seconds later will be a) 30m/s b) 40m/s c) 50m/s​

Answer 1

Answer is option (c)50m/s

Explanation:

Step 1

.Resolve or break the motion into horizontal and vertical components along the x- and y-axes. These axes are perpendicular, so  and are used. The magnitude of the components of displacement along these axes are  and  The magnitudes of the components of the velocity are  and  where 

 is the magnitude of the velocity and 

 is its direction, as shown in (Figure). Initial values are denoted with a subscript 0, as usual.

Step 2.

Treat the motion as two independent one-dimensional motions, one horizontal and the other vertical. The kinematic equations for horizontal and vertical motion take the following forms: