A 4-kilogram rock is tied to a string and a person swings the rock so that it travels in a horizontal circle. The string makes an angle of 38 degrees from the vertical (as shown above). What is the approximate amount of centripetal force on the rock?
How would I solve this problem? I have no clue how to use the mass
force = m * v^2 / r
the force (centripetal) is supplied by the tension in the string
f = t = m * g / sin(38º)