- #1

rain_ex

- 6

- 0

a. 390 N

b. 1000 N

c. 230 N *

d. 620 N

Can anyone check this for me? How I got this answer was: (I apologize for the lack of latex use)

- T = rev/time

- T = 2pi(radius)/4.5s

- T = 1.3956 radius/s

- N = (40kg)(1.9477radius/s)(8m) - (40kg)(9.8m/s^2) *used

- N = 231.262 N (closest to 230N, C)

2. Which requires a greater net force to maintain its circular path, a horse near the outside rail of a merry-go-round or a horse near the inside rail? *hint: the merry-go-round has the same rotational velocity at all points on the ride, but is the linear velocity the same for different radii?

a. the outside horse*

b. neither -- they both require the same net force

c. the inside horse

Can anyone check this for me? How I got this answer was:

The outside horse is obviously has a greater linear speed so that would mean the force has to be greater if both the radius and speed is greater, doesn't it?

3. From what height off the surface of Earth should an object be dropped to initially experience an acceleration of 0.5400 g's (5.292 m/s^2)? (Mass of earth = 5.974 x 10^24 kg, Radius of earth = 6.37 x 10^6 m )

a. 5.43 x 10^6 m

b. 1.69 x 10^6 m

c. 2.93 x 10^6 m

d. 3.56 x 10^6 m

e. 2.31 x 10^6 m

I don't really know where to start or how to solve this one. I tried using the universal law of gravitation but didn't know what to look for if the question refers to "height off the surface".

Help would be greatly appreciated. Thanks!