Question

if four balls ABCD are projected with the same speed at angle 15 degree 30 degree 45 degree and 60 degree with the horizontal respectively, the two balls which will fall at the same place will be
1, A & B. 2, A & D. 3, B & D. 4, A & C

Answer 1

Answer:

B & D

Explanation:

if four balls ABCD are projected with the same speed at angle 15 degree 30 degree 45 degree and 60 degree with the horizontal respectively, the two balls which will fall at the same place will be B & D

A Horizontal Speed = VCos15

Vertical Speed = V Sin15

time for max height = V Sin15/g

Time for range = 2V Sin15/g

Range = VCos15*2V Sin15/g = V²(2Sin15Cos15)/g

= V²(Sin(2*15)/g = V²Sin30/g = V²/2g

Similarly

B = V²(Sin(2*30)/g = V²Sin60/g = √3V²/2g

C = V²(Sin(2*45)/g = V²Sin90/g = V²/g

D = V²(Sin(2*60)/g = V²Sin120/g = √3V²/2g

B & D will fall at same place