The fastest speed before the string breaks is 9.5 m/s
Explanation:
The motion of the block is a uniform circular motion, which is a circular motion with constant speed. The force that keeps the block in circular motion is called centripetal force; its direction is towards the centre of the circle and its magnitude is given by:
![F=m\frac{v^2}{r}](https://tex.z-dn.net/?f=F%3Dm%5Cfrac%7Bv%5E2%7D%7Br%7D)
where
m is the mass of the block
v is its speed
r is the radius of the circle
In this problem, the centripetal force is provided by the tension in the string, T, so we can write:
![T=m\frac{v^2}{r}](https://tex.z-dn.net/?f=T%3Dm%5Cfrac%7Bv%5E2%7D%7Br%7D)
The string breaks when the centripetal force becomes larger than the maximum tension in the string:
![T_{max}](https://tex.z-dn.net/?f=T_%7Bmax%7D%3Cm%5Cfrac%7Bv%5E2%7D%7Br%7D)
Re-arranging the equation for v,
![v>\sqrt{\frac{Tr}{m}}](https://tex.z-dn.net/?f=v%3E%5Csqrt%7B%5Cfrac%7BTr%7D%7Bm%7D%7D)
and here we have:
T = 450 N
m = 10 kg
r = 2 m
Substituting,
![v>\sqrt{\frac{(450)(2)}{10}}=9.5 m/s](https://tex.z-dn.net/?f=v%3E%5Csqrt%7B%5Cfrac%7B%28450%29%282%29%7D%7B10%7D%7D%3D9.5%20m%2Fs)
So, the fastest speed before the string breaks is 9.5 m/s.
Learn more about circular motion:
brainly.com/question/2562955
brainly.com/question/6372960
#LearnwithBrainly