Answer:
21 m/s
Step-by-step explanation:
There are three forces on the pendulum:
Weight force mg pulling down,
Vertical tension component Tᵧ pulling up,
and horizontal tension component Tₓ pulling towards the center of the curve.
Sum of forces in the y direction:
∑F = ma
Tᵧ − mg = 0
T cos 37° = mg
T = mg / cos 37°
Sum of forces in the centripetal direction:
∑F = ma
Tₓ = mv²/r
T sin 37° = mv²/r
(mg / cos 37°) sin 37° = mv²/r
g tan 37° = v²/r
v = √(gr tan 37°)
v = √(9.8 m/s² × 60 m × tan 37°)
v = 21 m/s