C. The pressure decreases, and we can precisely predict by how much.
Answer:
0.88 cm
Explanation:
Initial length at 10°c, L = 23 m
Rise of temperature, Δt = 42 - 10 = 32°c
Coefficient of linear expansion of concrete, α = 12 x 10^(-6) per°c
Minimum spacing to be left = α L Δt


= 8.832 x 10^{-1} cm
= 0.88 cm
Note: I have a chosen a general value of 12 x 10^-6 per deg c for coefficient of expansion of concrete. However, please refer to the value given in your text book and substitute it for an accurate answer.
Answer:
When she stretches her arms out,<em> B) her angular speed ω increases due to her moment of inertia decreasing</em>
Explanation:
The angular momentum of a rotating object is defined as the product of its moment of inertia and angular speed.
<em>L = I ω</em>
<em>where</em>
- <em>L is the angular momentum</em>
- <em>I is the moment of inertia</em>
- <em>ω is the angular speed</em>
<em />
According to the principle of conservation of angular momentum, if there is no external torque, angular momentum of the skater must remain conserved. If the initial and final moment of inertia is <em>I_i and I_f </em>while corresponding angular velocities are <em>ω_i and ω_f , </em>then the principle of conservation of angular momentum can be expressed as the following equation:
<em>(I_f) (ω_f) = (I_i) (ω_i)</em>
<em>ω_f / ω_i = I_i / I_f</em>
<em />
From the expression above, we can see that if the moment of inertia decreases, angular velocity would increase to conserve angular momentum of the skater.
Therefore, When she stretches her arms out,<em> her angular speed ω increases due to her moment of inertia decreasing.</em>
Answer: 300 m/s
Explanation:
Given that:
length of water wave (λ) = 10 metres
Frequency of water wave (F) = 30 Hertz
Velocity of water wave (V) = ?
The velocity of a wave is the distance covered by the wave in one second. It is measured in metre per second, and represented by the symbol V. It is related to frequency and wave length by the formula: V = F λ
V = 30 Hertz x 10 metres
V = 300 m/s
Thus, the velocity of the water wave is 300 m/s
Answer:
3.39724 seconds
23.0824792352 m, 101.917520765 m
13.58896 m/s
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration
The equation of motion will be


The time at which the cars collide is 3.39724 seconds

Car B traveled 23.0824792352 m and Car A traveled 125-23.0824792352 = 101.917520765 m

The speed of car B is 13.58896 m/s