A body thrown up along a frictionless inclined plane of angle of inclination 30∘ covers a distance of 40 m along the plane. If the body id projected with the same speed at an angle of 30∘ with the ground, it will have a range of
(Take g=10 ms−2)
Let u be the initial speed with which the body is thrown along the inclined plane. As shown in the figure , the effective deceleration is given by
a=gsin θ=g sin 30∘=g2=5 ms−2
Now, from the third equation of motion,
A projectile projected at angle θ=30∘ with this speed will have a range of
R=u2 sin 2 θg=20×20×sin 60∘10=20√ m
Hence the correct choice is (c).