Answer:
t = 0.319 s
Explanation:
With the sudden movement of the athlete a pulse is formed that takes time to move along the rope, the speed of the rope is given by
v = √T/λ
Linear density is
λ = m / L
λ = 4/20
λ = 0.2 kg / m
The tension in the rope is equal to the athlete's weight, suppose it has a mass of m = 80 kg
T = W = mg
T = 80 9.8
T = 784 N
The pulse rate is
v = √(784 / 0.2)
v = 62.6 m / s
The time it takes to reach the hook can be searched with kinematics
v = x / t
t = x / v
t = 20 / 62.6
t = 0.319 s
The displacement is the distance from the beginning point to the ending point. The time was just to throw you off. If he walks 30m due west, and then 5m due east, his displacement would be 30-5=25m to the west.
Answer:
0.63 s
Explanation:
We have,
- Height, h = 2.0 m
- Initial velocity, u = 0 m/s
- Acceleration due to gravity, g = 10 m/s²
We have to find the time taken.
⠀⠀⠀⠀⇒ h = ut + ½gt²
⠀⠀⠀⠀⇒ h = ½gt²
⠀⠀⠀⠀⇒ 2 = ½ × 10 × t²
⠀⠀⠀⠀⇒ 2 = 5 × t²
⠀⠀⠀⠀⇒ 2/5 = t²
⠀⠀⠀⠀⇒ √(2/5) = t
⠀⠀⠀⠀⇒ <u>0.63 s = t</u>
Therefore, time taken is 0.63 seconds.
