Aroller-coaster car has a mass of 1080 kg when fully loaded with passengers. as the car passes over the top of a circular hill of radius 16 m, its speed is not changing. (a) at the top of the hill, what is the normal force (using the negative sign for the downward direction) fn on the car from the track if the car's speed is v = 7.6 m/s? (b) what is fn if v = 17 m/s? use g=9.81 m/s^2.

(a): The normal force on the car  from the track when the car's speed is v= 7.6 m/s  is  FN= -6696 N.

(b): The normal force on the car from the track when the car's speed is v= 17 m/s is FN= 8912.7 N.

Explanation:

m= 1080 kg

r= 16m

v1= 7.6 m/s

v2= 17 m/s

g= 9.81 m/s²

v1= w1*r

w1= v1/r

w1= 0.475 rad/s

ac1= w1² * r

ac1= 3.61 m/s²

FN= m * (ac1 - g)

FN= -6696 N    (a)

v2= w2*r

w2= v2/r

w2= 1.06 rad/s

ac2= w2² * r

ac2= 18.06 m/s²

FN= m * (ac2 - g)

FN= 8912.7 N    (b)

into the screen

explanation:

the wind is hitting the car into the screen

it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me