Q1. A car moves at a constant speed on a road as shown in figure. The normal force by the road on the car is (N_A) and (N_B), when it is at the points (A) and (B). Then relationship between (N_A) and (N_B) is
1) (N_A=N_B)
2) (N_A>N_B)
3) (N_A
4) cannot be predicted
Hint: At point A,
$$m g-N_A = \frac{m v^2}{r_A} \Rightarrow N_A = m g-\frac{m v^2}{r_A}$$
At point B ,
$$m g-N_B = \frac{m v^2}{r_B} \Rightarrow N_B = m g-\frac{m v^2}{r_B}$$
$$r_A
$$\frac{1}{r_A}>\frac{1}{r_B} \Rightarrow \frac{m v^2}{r_A}>\frac{m v^2}{r_B} \Rightarrow-\frac{m v^2}{r_A}<-\frac{m v^2}{r_B}$$
$$m g-\frac{m v^2}{r_A}
$$N_A