Laura B. answered • 10/22/21

Stress Free Studies! Math Tutor with MEd. UCSD, BS Physics UCSC

Hi Hope!

Use your centripetal acceleration equation along with a force equation, with the radius being the length of the line (6.20m), the speed of the skater is 6.75 m/s, and the mass you need to use being the mass of that farthest out skater (83.8kg).

so, centripetal acceleration is

a_{centripetal} = v^{2}/r

Multiply in by mass, and now you have the centripetal force because it's always true that force = mass X acceleration. Our Force Centripetal equation is:

F_{centripetal }= (mass)( a_{centripetal} ) = m (v^{2}/r) a_{centripetal}

Putting in our values we get:

m (v^{2}/r) a_{centripetal} = (83.8_{kg})(6.75_{m/s}^{2})/(6.2_{m})

Crank through those numbers--remembering that (6.75_{m/s}^{2}) means multiply 6.75 by itself (not by 2) and you should get the correct answer in Newtons.

Let me know if it works out for you!

Cheers,

Laura

P.S. I got 615.8N. What did you get?

Hope M.

I got the same answer. Thank you so much!10/22/21