Answer:
a) Wavelength of the ultrasound wave = 0.0143 m <<< 3.5m, hence its ability is not limited by the ultrasound's wavelength.
b) Minimum time difference between the oscillations = Period of oscillation = 0.00952 ms
Explanation:
The frequency of the ultrasound wave = 105 KHz = 105000 Hz. The speed of ultrasound waves in water ≈ 1500 m/s. Wavelength = ?
v = fλ
λ = v/f = 1500/105000 = 0.0143 m <<< 3.5m
This value, 0.0143m is way less than the 3.5m presented in the question, hence, this ability is not limited by the ultrasound's wavelength.
b) Minimum time difference between the oscillations = The period of oscillation = 1/f = 1/105000 = 0.00000952s = 0.00952 ms
Hope this helps!
Answer:
σ = 0.255*10^-3 C/m²
Explanation:
The Electric field Intensity act due to plate = σ/ε₀, where σ is surface charge density of plate.
At equilibrium ,
Upward force = downward force
Tcosθ = mg ----(1)
Assuming that the Forward force = backward force, then
Tsinθ = σq/ε₀
[ ∵ F = qE , ∴ F = qσ/ε₀ ] -----(2)
Dividing equation (2) by (1)
Tsinθ/Tcosθ = qσ/ε₀mg
⇒Tanθ = qσ/ε₀mg
σ = ε₀mg tanθ/q
Now substituting the values of
σ = (8.85*10^-12 * 1 * tan 30) / 2*10^-8
σ = (8.85*10^-12 * 0.5774) / 2*10^-8
σ = 5.11*10^-12 / 2*10^-8
σ = 0.255*10^-3 C/m²
observer is standing at distance d = 60 m south from the intersection
cyclist is travelling at speed v = 10 m/s
now after t = 8 s its displacement from intersection is given by

so the position of cyclist makes an angle with the observer

now the component of velocity of cyclist along the line joining its position with the observer is given as

here



so at this instant cyclist is moving away with speed 8 m/s
Answer:
The maximum speed of the car at the bottom of that drop is 26.34 m/s.
Explanation:
Given that,
The maximum vertical distance covered by the roller coaster, h = 35.4 m
We need to find the maximum speed of the car at the bottom of that drop. It is a case of conservation of energy. The energy at bottom is equal to the energy at top such that :



v = 26.34 m/s
So, the maximum speed of the car at the bottom of that drop is 26.34 m/s. Hence, this is the required solution.