What is the speed of the block?What is the tension in the string?

Question

A 200g block on a 50 meter string swings in a circle on a horazontal, frictionless table at 75 rpm.

Answer 1

SKR is on right track. I would like to stress that equations are important

V=2 pi R (RPS)
RPS=RPM/60 (1minute=60 seconds)

F=ma
a=(V^2)/R
a=((2 pi R (RPS))^2)/R=
a=4 (pi)^2 R (RPS)^2=
F=ma=.2 (4)(3.14)^2 50 (75/60)^2=617 N

Answer 2

speed of block=50*2*3.14*(75/60)

tension=
.2*50*[2*3.14*(75/60)]^2