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:
C. crust, mantle, core
Explanation:
density increases as you travel from the crust to the inner core
the crust is on top
next is the mantle
and then the core
Answer:
44.13015
Explanation:
use the 9.8067 newtons to 1 kg conversion
Mass of the displaced material. In water it would be the mass of the water that the volume of the ball displaces.
Answer:
84.82N/C.
Explanation:
The x-components of the electric field cancel; therefore, we only care about the y-components.
The y-component of the differential electric field at the center is
.
Now, let us call
the charge per unit length, then we know that
;
therefore,


Integrating

![$E = \frac{k \lambda }{R}*[-cos(\pi )+cos(0) ]$](https://tex.z-dn.net/?f=%24E%20%3D%20%5Cfrac%7Bk%20%5Clambda%20%20%20%7D%7BR%7D%2A%5B-cos%28%5Cpi%20%29%2Bcos%280%29%20%5D%24)

Now, we know that


and the radius of the semicircle is

therefore,

