- #1

Iamconfused123

- 66

- 9

- Homework Statement
- A person with a mass of 50kg is spinning on a Ferris wheel. The radius is 5m. If the wheel spins with a constant speed of 5m/s, what will be the force of the chair acting on the person (Normal force) at the highest and lowest point of the spin?

- Relevant Equations
- ##F_{cp}=mv^2/r##, ##F=ma##, ##a=v^2/r## ##g=10m/s^2##

I don't understand why am I getting opposite answers. I get 250N for the lowest point and 750 for the highest point.

For the highest point: ##F_{net}=F_{cp}+F_{mg}-F_N## and then ##F_N=ma_{cp}+mg = 50*(25/5)+500=750N## because I've been told that ##F_{cp}## always acts towards the center of the circle and that that is always positive direction, which in this case is downwards which also makes ##F_g## positive.

But even if I reverse the signs. If I make upwards positive and downwards negative I'll get the same answer; ##F_{net}= -F_{cp}-F_{mg}+F_N## because when ##F_N## gets to ghe left it becomes negative and then all forces are negative. Multiply by -1 and we get 750N again as a result.

for the lowest point: ##F_{net}=F_{cp}-F_{mg}+F_N## and that is ##F_N=-ma_{cp}+mg = -50*(25/5)+500 = 250N## and if I reverse the signs and make upwards negative I will still get same result .

Can someone please tell me where I am wrong. Than you very much.

For the highest point: ##F_{net}=F_{cp}+F_{mg}-F_N## and then ##F_N=ma_{cp}+mg = 50*(25/5)+500=750N## because I've been told that ##F_{cp}## always acts towards the center of the circle and that that is always positive direction, which in this case is downwards which also makes ##F_g## positive.

But even if I reverse the signs. If I make upwards positive and downwards negative I'll get the same answer; ##F_{net}= -F_{cp}-F_{mg}+F_N## because when ##F_N## gets to ghe left it becomes negative and then all forces are negative. Multiply by -1 and we get 750N again as a result.

for the lowest point: ##F_{net}=F_{cp}-F_{mg}+F_N## and that is ##F_N=-ma_{cp}+mg = -50*(25/5)+500 = 250N## and if I reverse the signs and make upwards negative I will still get same result .

Can someone please tell me where I am wrong. Than you very much.