A ball whose kinetic energy is E is thrown at an angle of 45∘ with the horizontal. Its kinetic energy at the highest point of its trajectory will be:
E2
Let m be mass of the ball. If v is its speed of projection, its kinetic energy is
E=12mv2
At the highest point, the velocity of the particle is v′=v cos θ=v cos 45∘=v√2. Therefore its kinetic energy at this point is
E′=12mv′2=12m(v√2)2=12×12mv2=E2
Hence, the correct choice is (c).