Harold Kessler

2022-01-14

A 300 g block on a 56.0 cm-long string swings in a circle on a horizontal, frictionless table at 90.0 rpm.
A) What is the speed of the block?
B) What is the tension on the string?

scoollato7o

Expert

The angular speeed is,

$=9.425\text{rad/s}$
b) The centripetal force acting on the block must counterbalance the force of tension..
$T=\frac{m{v}^{2}}{r}$
$=\frac{300\left(\frac{{10}^{-3}}{1.0}\right)\left(5.28\right)}{0.56}$

RizerMix

Expert

The angular speeed is, $=9.425\text{rad/s}$ a) The speed of the block is, $v=\omega r$

alenahelenash

Expert

a) $w=70\ast 2\ast 3.14/60=7.327\left(rad\right)/s$ $v=w\ast r=7.327\ast 0.6=4.396m/s$ b) $T=\left(m{v}^{2}\right)/r=0.26\ast {4.396}^{2}/0.6=8.374N$