Question icon
Grade 11Mechanics

A projectile is fired from the top of a 40 m high cliff with an initial speed of 50 m/s at an unknown angle. Find its speed when it hits the ground.

Profile image of Radhika Batra
12 Years agoGrade 11
Answers icon

1 Answer

Profile image of Navjyot Kalra
12 Years ago
Sol. h = 40m, u = 50 m/sec Let the speed be ‘v’ when it strikes the ground. Applying law of conservation of energy mgh + ½ mu2 = ½ mv2 ⇒ 10 × 40 + (1/2) × 2500 = ½ v^2 ⇒ v^2 = 3300 ⇒ v = 57.4 m/sec =58 m/sec