Answer:
A. 20 N down
Explanation:
It's asking how much force of gravity is acting on it. The book weighs 20 Newtons so that's how much gravity is being applied. Hope this helps
To solve this problem we will apply the concepts related to the centripetal Force and the Force given by weight and formulated in Newton's second law. Through the two expressions we can find the radius of curve made in the hand. To calculate the normal force, we will include the concepts of sum of forces to obtain the net force on the body at the top and bottom of the maneuver. The expression for centripetal force acting on the jet is

According to Newton's second law, the net force acting on the jet is
F = ma
Here,
m = mass
a = acceleration
v = Velocity
r = Radius
PART A ) Equating the above two expression the equation for radius is


Replacing with our values we have that
![r = \frac{(1140km/hr[\frac{1000m}{1km}\frac{1hour}{3600s}])^2}{7(9.8m/s^2)}](https://tex.z-dn.net/?f=r%20%3D%20%5Cfrac%7B%281140km%2Fhr%5B%5Cfrac%7B1000m%7D%7B1km%7D%5Cfrac%7B1hour%7D%7B3600s%7D%5D%29%5E2%7D%7B7%289.8m%2Fs%5E2%29%7D)

PART B )
<u>- The expression for effective weight of the pilot at the bottom of the circle is</u>

![N = (69kg)(9.8m/s^2)+\frac{(69)(1140km/hr[\frac{1000m}{1km}\frac{1hour}{3600s}])^2}{1.462*10^3m}](https://tex.z-dn.net/?f=N%20%3D%20%2869kg%29%289.8m%2Fs%5E2%29%2B%5Cfrac%7B%2869%29%281140km%2Fhr%5B%5Cfrac%7B1000m%7D%7B1km%7D%5Cfrac%7B1hour%7D%7B3600s%7D%5D%29%5E2%7D%7B1.462%2A10%5E3m%7D)

<em>Note that the normal reaction N is directed upwards and gravitational force mg is directed downwards. At the bottom of the circle, the centripetal force is directed upwards. So the centripetal force is obtained from the gravitational force and the normal reaction. </em>
<u>- The expression for effective weight of the pilot at the top of the circle is</u>

![N = (69kg)(9.8m/s^2)-\frac{(69)(1140km/hr[\frac{1000m}{1km}\frac{1hour}{3600s}])^2}{1.462*10^3m}](https://tex.z-dn.net/?f=N%20%3D%20%2869kg%29%289.8m%2Fs%5E2%29-%5Cfrac%7B%2869%29%281140km%2Fhr%5B%5Cfrac%7B1000m%7D%7B1km%7D%5Cfrac%7B1hour%7D%7B3600s%7D%5D%29%5E2%7D%7B1.462%2A10%5E3m%7D)

<em>Note that at the top of the circle the centripetal force is directed downwards. So the centripetal force is obtained from normal reaction and the gravitational force. </em>
Answer the point I wish you would have the greatest potential energy is when you are coming down the swing and getting ready to go up the greatest kinetic energy is whenever you’re falling back down from the height of how far you went up
Common examples include the reflection of light, sound and water waves. The law of reflection says that for specular reflection the angle at which the wave is incident on the surface equals the angle at which it is reflected. Mirrors exhibit specular reflection.