It increases, because the centripetal acceleration is inversely proportional to the radius of the curvature.
Hopr it helps :)
The velocity is 60 because you divide your distance by your time (240÷4=60)
A) 
Let's start by writing the equation of the forces along the directions parallel and perpendicular to the incline:
Parallel:
(1)
where
m is the mass
g = 9.8 m/s^2 the acceleration of gravity

is the coefficient of friction
R is the normal reaction
a is the acceleration
Perpendicular:
(2)
From (2) we find

And substituting into (1)

Solving for a,

B) 5.94 m/s
We can solve this part by using the suvat equation

where
v is the final velocity
u is the initial velocity
a is the acceleration
s is the displacement
Here we have
v = ?
u = 0 (it starts from rest)

s = 8.70 m
Solving for v,

Answer:
magnitude of gravitational force between the Earth and the Sun at B is greater than that at A
Explanation:
Formula of gravitational force:
F = GMm/r^2
(r is the distance between 2 objects)
We see that r(B) < r(A) since at B, the Earth is closer to the Sun than at A
According to the Formula, the smaller r is, the greater F is
So, F(B) > F(A)