Answer:
Explanation:
Given
Distance to grandmother's house=100 mi
it is given that during return trip Julie spend equal time driving with speed 30 mph and 70 mph
Let Julie travel x mi with 30 mph and 100-x with 70 mph

x=30 mi
Therefore
Julie's Average speed on the way to Grandmother's house
=42 mph
On return trip

Answer:
F = 2985.125 N
Explanation:
Given that,
The radius of curvature of the roller coaster, r = 8 m
Speed of Micheal, v = 17 m/s
Mass of body, m = 65 kg We need to find the net force acting on Micheal. Net force act the bottom of the circle is given by :

So, the net force is 2985.125 N.