AP EAMCET202124 Aug 2021Morning ShiftPhysicsMotion in Two DimensionsActual
From the top of a tower 19.6 ~m high, a ball is thrown horizontally. If the line joining the point of projection to the point where it hits the ground makes an angle of 45^ with the horizontal, then the initial velocity of the ball is
Options
- A9.8 ~ms ⁻¹
- B4.9 ~ms ⁻¹
- C14.7 ~ms ⁻¹
- D2.8 ~ms ⁻¹
Correct answer
A. 9.8 ~ms ⁻¹
Step-by-step solution
Given that, height of tower, h=19.6 ~m Angle of line joining from point of projection to the point of ground with horizontal, aligned & =45^ In A O B, & = h R 45^ & = h R 1= h R R & =h=19.6 ~m aligned where, R be the horizontal distance. We know that, time taken to reach from point A to B , t= 2 h g By substituting the values, we get t= 2 19.6 9.8 =2 ~s Now, Horizontal distance = Horizontal velocity Time aligned & R=u t & 19.6=u 2 & aligned [By substituting the values of R and t , we get] Initial velocity, u=9.8 ~m