Answer:
The tension in the cable when the craft was being lowered to the seafloor is 4700 N.
Explanation:
Given that,
When the craft was stationary, the tension in the cable was 6500 N.
When the craft was lowered or raised at a steady rate, the motion through the water added an 1800 N.
The drag force of 1800 N will act in the upward direction. As it was lowered or raised at a steady rate, so its acceleration is 0. As a result, net force is 0. So,
T + F = W
Here, T is tension
F = 1800 N
W = 6500 N
Tension becomes :
So, the tension in the cable when the craft was being lowered to the seafloor is 4700 N.
Answer:
The time taken by the rock to reach the ground is 0.569 seconds.
Explanation:
Given that,
A student throws a rock horizontally off a 5.0 m tall building, s = 5 m
The initial speed of the rock, u = 6 m/s
We need to find the time taken by the rock to reach the ground. Using second equation of motion to find it. We get :
So, the time taken by the rock to reach the ground is 0.569 seconds. Hence, this is the required solution.
Answer:
t = 0.37 seconds
Explanation:
t = (1/4)T
Maximum acceleration is;
a_max = Aω²
In simple harmonic motion, we know that v_max = Aω
Thus, a_max = v_max•ω
ω = a_max/v_max
We know that Period is given by;
T = 2π/ω
From initially, t = (1/4)T so, T = 4t
Thus, 4t = 2π/(a_max/v_max)
t = (2π/4)(v_max/a_max)
We are given;
Maximum velocity;v_max = 1.47 m/s
Max acceleration;a_max =6.24 m/s²
Thus,
t = (2π/4)(1.47/6.24)
t = 0.37 seconds
Answer: 2.86 m
Explanation:
To solve this question, we will use the law of conservation of kinetic and potential energy, which is given by the equation,
ΔPE(i) + ΔKE(i) = ΔPE(f) + ΔKE(f)
In this question, it is safe to say there is no kinetic energy in the initial state, and neither is there potential energy in the end, so we have
mgh + 0 = 0 + KE(f)
To calculate the final kinetic energy, we must consider the energy contributed by the Inertia, so that we then have
mgh = 1/2mv² + 1/2Iw²
To get the inertia of the bodies, we use the formula
I = [m(R1² + R2²) / 2]
I = [2(0.2² + 0.1²) / 2]
I = 0.04 + 0.01
I = 0.05 kgm²
Also, the angular velocity is given by
w = v / R2
w = 4 / (1/5)
w = 20 rad/s
If we then substitute these values in the equation we have,
0.5 * 9.8 * h = (1/2 * 0.5 * 4²) + (1/2 * 0.05 * 20²)
4.9h = 4 + 10
4.9h = 14
h = 14 / 4.9
h = 2.86 m
This may shock you:
We NEVER feel speed, velocity, or motion, as long as it's constant.
We only feel CHANGES in speed, velocity, or motion.
That means speeding up, slowing down, or changing direction.
As long as we're moving in a straight line at a constant speed, we don't feel anything.
