one end of a string of length l = 14/9 m is fixed and a mass of 1kg is tied to the other end. the ball is given a velocity 2√gl at the bottom most point as shown in figure. The string is cut when the ball becomes horizontal. Find the distance(in m) travelled till it stop for the 1st time (Take π = 22/7)
Answers
Given info : one end of a string of length l = 14/9 m is fixed and a mass of 1kg is tied to the other end. the ball is given a velocity 2√gl at the bottom most point as shown in figure. The string is cut when the ball becomes horizontal.
To find : the distance travelled till it stops for the 1st time.
solution : velocity of ball when string becomes horizontal, v
using formula, v² = u² + 2gh
⇒v² = (2√gl)² + 2g(-l) = 4gl - 2gl = 2gl
⇒v² = 2gl
now height attained by ball after cutting the string, h = v²/2g = 2gl/2g = l
so the distance travelled by ball = distance from bottom to horizontal in circular motion + height attained by ball after cutting the string.
= 2πl/4 + l
= 2 × 22/7 × 14/9 × 1/4 + 14/9
= 22/9 + 14/9
= 36/9
= 4m
Therefore the distance travelled by ball till it stops for the 1st time is 4 m.
Answer:
4m
Explanation:
correct explanation is given in the image
you can see this from there
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