240,474 views
5 votes
5 votes
.

A 2155 kg demolition ball swings at the end of a 17.5m cable on the arc of a vertical
circle. At the lowest point of the swing, the ball is moving at 8.6m/s. Determine the
tension in the cable at the lowest point. (Hint: T-mg =mv^2/r)

User Mark McClelland
by
2.5k points

1 Answer

15 votes
15 votes

Answer:

Thread tension:

T = F + P = 9 108 + 21 120 ≈ 30 230 N

Step-by-step explanation:

Given:

m = 2155 kg

R = 17.5 m

V = 8.6 m/s

g = 9.8 m/s²

_______________

T - ?

Modulus of centripetal force (force is directed towards the center of the circular arc):


F = (m\cdot V^2)/(R) = (2155\cdot 8.6^2)/(17.5) = 9108 N

Ball weight (directed vertically down):

W = m·g = 2155·9.8 ≈ 21 120 N

Let's use the hint. Thread tension:

T = F + W = 9 108 + 21 120 ≈ 30 230 N

User Cowborg
by
3.1k points