Answer:
7 ms⁻¹
Explanation:
When the weight is 50% more, if the actual weight is W, the weight at the dip will be 1.5 Mg . At the bottom, the forces acting are
Weight Mg , vertically downwards
Centripetal force towards the center of the circle
and the normal force N = 1.5 Mg, that acts towards the center
N - Mg = Mv²÷ r
1.5 Mg - Mg = M v² ÷ r
0.5 g = v² ÷ 10
⇒ v = 7 ms⁻¹ Car's speed at the bottom of the dip.