Answer:

Explanation:
From the question we are told that
Radius of vertical r= 8m
Force exerted by passengers is 1/4 of weight
Generally the net force acting on top of the roller coaster is give to be

where


Generally the net force is given to be 




Mathematical we can now derive V




Therefore the speed of the roller coaster is given ton be 
Answer:
Vb = k Q / r r <R
Vb = k q / R³ (R² - r²) r >R
Explanation:
The electic potential is defined by
ΔV = - ∫ E .ds
We calculate the potential in the line of the electric pipe, therefore the scalar product reduces the algebraic product
VB - VA = - ∫ E dr
Let's substitute every equation they give us and we find out
r> R
Va = - ∫ (k Q / r²) dr
-Va = - k Q (- 1 / r)
We evaluate with it Va = 0 for r = infinity
Vb = k Q / r r <R
We perform the calculation of the power with the expression of the electric field that they give us
Vb = - int (kQ / R3 r) dr
We integrate and evaluate from the starting point r = R to the final point r <R
Vb = ∫kq / R³ r dr
Vb = k q / R³ (R² - r²)
This is the electric field in the whole space, the places of interest are r = 0, r = R and r = infinity
Answer:
Distance covered by B is 4 times distance covered by A
Explanation:
For an object in free fall starting from rest, the distance covered by the object in a time t is

where
s is the distance covered
g is the acceleration due to gravity
t is the time elapsed
In this problem:
- Object A falls through a distance
during a time t, so the distance covered by object A is

- Object B falls through a distance
during a time 2t, so the distance covered by object B is

So, the distance covered by object B is 4 times the distance covered by object A.
Velocity = displacement / time
First, Always make sure that your units for things are the same. In this question, we are given time in seconds and hours. So, we need to make them all use 1 unit.
I will do seconds.
To convert 80km/h to m/s, divide by 3.6.
22.2222…. m/s = displacement / 2.1s
Multiply by 2.1s on both sides
46.6666……m = displacement
You travelled 47 meters.