a string 2m long used to whirl a 200gm stone in horizontal circle at a speed of 2m/s . find the tension in the string​

Explanation:

First off, we need the mass in kg and it's in g so we have to convert it. Then we can do the problem. 200 g = .200 kg. Moving on.

The equation used to find the tension in the string is the same one we use to find the centripetal force, because the tension is what is upplying the centripetal force needed to keep the stone moving in a circular manner. The formula for that is

where ma is the mass in kg, v is the velocity in m/s, and r is the radius of the circle about which the stone spins in meters.

Filling in:

which gives us

T = .4 N

54 degrees incident angle = reflected angle

angle is from normal turned to line of ray