Centripetal Force Calculation for Hanging Partner

[jehan4141]

Will you please tell me if my work is correct? My professor said to ask my TA for the even answers in prep for my quizzes on Fridays, but the TA told me there is no way to access even answers...somebody is not being honest. Anyhow, any help would be great. Thank you!

In Figure 5.8 the man hanging upside down is holding a partner who weighs 475 N. Assume that the partner moves on a circle that has a radius of 6.50 m. At a swinging speed of 4.00 m/s, what force must the man apply to his partner in the straight-down position?

Wp = 475 N
Mp = 475/9.8 = 48.46938776 kg
r = 6.5 m
V = 4 m/s

F_C = mv² / r = (48.469)(4² / 6.5 = 119.31 N
F_total = F_C + Wp = 119.31 + 475 = 594.31 N

 

[grzz]

Correct.
But I would have started from Newton's 2nd law:
resultant force = m x acc (towards centre of circle)
Fpartner - wt of hanging man = m x centripetal acc

 

[jehan4141]

Thank you and for the tip!