Answer:
(a) 4.4 m/s²
(b) 4.615 N.
(c) 0.751 J
Explanation:
(a)
Using,
a' = v²/r..................... Equation 1
Where a' = centripetal acceleration, v = speed of the pendulum bob, r = radius or length of the pendulum bob.
Given: v = 2.15 m/s, r = 105 cm = 1.05 m
Substitute into equation 1
a' = 2.15²/1.05
a' = 4.4 m/s².
(b) The force of tension in the string = Tangential force + weight of the bob.
T = ma'+mg..................... Equation 2
Where T = Force of tension in the string, m = mass of the bob, g = acceleration due to gravity.
Given: m = 325 g = 0.325 kg, a' = 4.4 m/s², g = 9.8 m/s²
Substitute into equation 2
T = 0.325×4.4+0.3325×9.8
T = 1.43+3.185
T = 4.615 N.
(c) Kinetic energy of he bob at that point = 1/2mv²
Ek = 1/2mv²...................... Equation 3
Where Ek = kinetic energy of the bob
Given: m = 0.325 kg, v = 2.15 m/s
Substitute into equation 3
Ek = 1/2(0.325)(2.15²)
Ek = 0.751 J
