Question

A ball weighing 60 N is swinging like a pendulum at the end of a 6.0 m rope. As the ball swings through its lowest point, its speed is measured at 5.0 m/s. What is the tension in the rope at this point?
A. 58.6 N
B. 85.4 N
C. 90.2 N
D. 97.3 N

Answer 1

Answer:

85.4 N

Explanation:

Weight of the ball, W = 60 N

W = mg, m is mass

m = W/g

m = 60/9.8 = 6.12 kg

Length of a rope, r = 6 m

Speed, v = 5 m/s

We need to find the tension in the rope at this point. Tension is equal to the centripetal force It is given by :

$F=\dfrac{mv^2}{r}+mg\\\\F=\dfrac{6.12\times (5)^2}{6}+60\\\\=85.5\ N$

So, the correct option is (b) " 85.4 N".