Answer:
a) y = 400 ft b) y = 350 ft
Explanation:
We can solve that problem with kinematic relationships
y = v₀ t + ½ a t²
Let's apply this equation to the elevator 1
y₁ = v₀ t₁ + ½ to t₁²
time t= 1 s
y₁ = v₀ 1 + ½ a 1²
y₁ = v₀ + ½ a
For t = 2s
y₂ = v₀ 2 + ½ a 2²
y₂ = 2 v₀ + 2 a
Let's write the equations and solve the system
4 = v₀ + ½ a
9 = 2 v₀ + 2 a
Let's multiply the first by -2
-8 = -2v₀ -a
9 = 2v₀ + 2 a
Let's add
1 = a
We replace in the first
4 = v₀ + ½ 1
v₀ = 4- 1/2
v₀ = 3.5
The equation for the first elevator is
y = 3.5 t + ½ t²
For t = 10 s
y = 3.5 10 + ½ 10²
y = 400 ft
We repeat the process for the second elevator
t = 1s
y₁ = v₀ 1 + ½ a 1²
3.5 = v₀ + ½ a
t = 2 s
y₂ = v₀ 2 + ½ a 2²
6.5 = 2 v₀ +2 a
multiply by -2
-7 = -2 v₀ - a
6.5 = 2 v₀ + 2 a
Let's add
-0.5 = a
I replace in the first equation
3.5 = v₀ + ½ (-0.5)
v₀ = 3.5 + 0.25
v₀ = 3.75
The equation is
y = 3.75 t -0.25 t²
For t = 10s
y = 3.75 10 - 0.25 10²
y = 350 ft
Answer:
a.) high amplitude, high frequency
Explanation:
Frequency and amplitude are properties of sound. Varying these properties changes how people perceive sound.
While hearing sound of a particular frequency we call it pitch i.e., the perception of a frequency of sound.
High pitch means high frequency and high frequency is perceived to have a shrill sound.
The loudness of a sound is measured by the intensity of sound i.e., the energy the sound possesses per unit area. As the amplitude increases the intensity increases. So, a loud sound will have higher density.
Hence, the loud shrill whistle will have high frequency and high amplitude.
Answer:
reading would be 5.413 m.
Explanation:
Given:-
- The actual distance from ruler to an object is d = 24.0 m
- The adiabatic bulk modulus, B = 2.37 *10^9 Pa
- The density of seawater, ρ = 1025 kg/m^3
- The preset value of speed of sound in air, v_th = 343 m/s.
Find:-
Determine the distance reading that the ruler displays.
Solution:-
- We will first determine the actual speed of the sound ( v_a) in sea-water which can be determined from the following formula:
v_a = √ (B / ρ )
- Plug in the values in the relationship above and compute v_a:
v_a = √ ( 2.37 *10^9 / 1025 )
v_a = 1520.59038 m/s
- The time taken (t) for for the sound to travel from source(ruler) to an object which is d distance away.
d = v_a*t
t = d / v_a
t = 24.0 / 1520.59038
t = 0.01578 s
- The distance reading on the ruler would be preset speed (v_th) of sound in air multiplied by the time taken(t).
reading = v_th*t
reading = (343)*(0.01578)
= 5.413 m
Is b= acid + base - water + salt.
Answer:
speed of car = 95 km/h
speed of truck = 75 km/h
relative speed of car with respect to truck = 95 - 75 = 20 km/h
now we will convert it into m/s
now time to cross the truck will be given as
time = 19.8 s
so it will take 19.8 s to cross the truck
Explanation:
