# Physics

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How do you solve this problem?
A ball on the end of a string is revolved at a uniform rate in a vertical circle radius of 72.0 cm, as shown in figure. If its speed is 4.00m/s and its mass is .300 kg. Calculate the tension in the string when the ball is a) at the top of the path, and b). when it's at the bottom?

• Physics -

a) Mg + T = MV^2/R
T = M(V^2/R -g)

b) T - Mg = MV^2/R
T = M(V^2/R + g)

T is the tension that you want to compute.
Make sure R is in meters when you do the calculation. The force will be in Newtons.

• Physics -

Can you like work the problem out so i can see how it is done?

• Physics -

what is the V in this case? That's what throwing me off..

• Physics -

V is velocity, given as 4m/s

• Physics -

Okay, I worked them out, but I am not getting the answer they should be. Like a) i am getting as what should be the answer as b. So, i don't if someone could work them out or tell me maybe what doing wrong. Thanks!

• Physics -

All you have to do is use the formulas provided, using these variables:
V = 4.0 m/s
M = 0.3 kg
g = 9.8 m/s^2
R = 0.72 m

• Physics -

Okay, so for a) get 3.13 and b). get 16.5?