The Total solution for NCERT class 6-12
The escape speed of a projectile on theearth’s surface is 11.2 km s–1. A body is projected outwith thrice this speed. What is the speed of the body far away from the earth?Ignore the presence of the sun and other planets.
Escape velocity of a projectile from theEarth, vesc = 11.2 km/s
Projection velocity of the projectile, vp = 3vesc
Mass of the projectile = m
Velocity of the projectile far away from theEarth = vf
Gravitational potentialenergy of the projectile far away from the Earth is zero.
From the law ofconservation of energy, we have