Answer:
Force, F = 187.42 N
Explanation:
It is given that,
Mass of boy, m = 30 kg
Acceleration due to gravity, 
Radius of curvature of the roller coaster, r = 15 m
Speed of the car, v = 7.3 m/s
The force acting on the boy are force of gravity and the centripetal force. The net force acting on him is as follows :



F = 187.42 N
So, he press against the seat with a force is 187.42 N. Hence, this is the required solution.
Answer:
speed = distance/time
Explanation:
speed = 150/30
speed =5m/s
you were running fast .....5m/s is a good speed
Answer:
Acceleration, 
Explanation:
It is given that,
Separation between the protons, 
Charge on protons, 
Mass of protons, 
We need to find the acceleration of two isolated protons. It can be calculated by equating electric force between protons and force due to motion as :


So, the acceleration of two isolated protons is
. Hence, this is the required solution.
Answer:
25 mm = 0 deg C
200 mm = 100 deg C
200 - 25 = 175 = change in thread per 100 deg C
95 - 25 = 70 mm - change in thread from 0 deg C
70 / 175 * 100 = 40 deg C final temperature at 95 mm