JEE Main2014PhysicsGravitationActual
The gravitational field in a region is given by g → = 5 i ^ + 12 j ^ N kg - 1 . The change in the gravitational potential energy of a particle of mass 2 kg when it is taken from the origin to a point 7 m , - 3 m is
Options
- A71 J
- B1 3 5 8 J
- C2 J
- D1     J
Correct answer
C. 2 J
Step-by-step solution
d V = - g → . d r → ⇒ ∆ V = - g → . ∆ r → = - 5 i ^ + 1 2 j ^ · 7 i ^ - 3 j ^ = - 3 5 - 3 6 = 1 ⇒Δ U = m Δ V = 2 J