Answer:
a)

b) 
Explanation:
The net force on the car must produce the centripetal acceleration necessary to make this circle, which is
. At the top of the circle, the normal force and the weight point downwards (like the centripetal force should), while at the bottom the normal force points upwards (like the centripetal force should) and the weight downwards, so we have (taking the upwards direction as positive):

Which means:

The limit for falling off would be
, so the minimum speed would be:

Answer:
25 min, 48 sec
Explanation:
Alan:
t = d/v
= 400 mi / 46 mph = 8.70 hr
So it took Alan 8.70 hrs; from 8 am, that's 4:42 pm that he arrives.
t = d/v
= 400 mi / 55 mph = 7.27 hr
So it took Beth 7.27 hrs; from 9 am, that's 4:16:12 that she arrives.
4:42 - 4:16:12 = 25.8 minutes = 25 minutes, 48 sec
Answer:
The pressure is 
Explanation:
From the question we are told that
The depth of the swimming pool is 
The density of water is 
Generally the total pressure exerted on the bottom of the swimming pool is mathematically represented as

Here
is the atmospheric pressure with value
So
![P = 101325 + [1000 * 9.8 * 3]](https://tex.z-dn.net/?f=P%20%3D%20101325%20%2B%20%5B1000%20%2A%209.8%20%2A%203%5D)
=> 
=> 
Answer:
1.503 J
Explanation:
Work done in stretching a spring = 1/2ke²
W = 1/2ke²........................... Equation 1
Where W = work done, k = spring constant, e = extension.
Given: k = 26 N/m, e = (0.22+0.12), = 0.34 m.
Substitute into equation 1
W = 1/2(26)(0.34²)
W = 13(0.1156)
W = 1.503 J.
Hence the work done to stretch it an additional 0.12 m = 1.503 J