When a particle is projected at an angle of 15° from horizontal, it’s range is found to be 3.5 m. What would be it’s range (in m) if it is projected at an angle of 45° from horizontal with same speed?
Physics · Kinematics part-2 Projectile Motion · Motion in 2-D and ground to ground projectile
JEE Advanced

Question

When a particle is projected at an angle of 15° from horizontal, it’s range is found to be 3.5 m. What would be it’s range (in m) if it is projected at an angle of 45° from horizontal with same speed?

Physics · Kinematics part-2 Projectile Motion · Motion in 2-D and ground to ground projectile

G1 Physics · Accepted Answer

For the same speed, R ∝ sin2θ. At 15°, 3.5 = K sin30° = K/2, so K = 7 m. At 45°, sin90° = 1, hence R = 7 m. Therefore the answer is 7.