Answer: V = 15 m/s
Explanation:
As stationary speed gun emits a microwave beam at 2.10*10^10Hz. It reflects off a car and returns 1030 Hz higher. The observed frequency the car will be experiencing will be addition of the two frequency. That is,
F = 2.1 × 10^10 + 1030 = 2.100000103×10^10Hz
Using doppler effect formula
F = C/ ( C - V) × f
Where
F = observed frequency
f = source frequency
C = speed of light = 3×10^8
V = speed of the car
Substitute all the parameters into the formula
2.100000103×10^10 = 3×10^8/(3×10^8 -V) × 2.1×10^10
2.100000103×10^10/2.1×10^10 = 3×108/(3×10^8 - V)
1.000000049 = 3×10^8/(3×10^8 - V)
Cross multiply
300000014.7 - 1.000000049V = 3×10^8
Collect the like terms
1.000000049V = 14.71429
Make V the subject of formula
V = 14.71429/1.000000049
V = 14.7 m/s
The speed of the car is 15 m/s approximately
Answer:
2.87 km/s
Explanation:
radius of planet, R = 1.74 x 10^6 m
Mass of planet, M = 7.35 x 10^22 kg
height, h = 2.55 x 10^6 m
G = 6.67 x 106-11 Nm^2/kg^2
Use teh formula for acceleration due to gravity
g = 1.62 m/s^2
initial velocity, u = ?, h = 2.55 x 10^6 m , final velocity, v = 0
Use third equation of motion
0 = v² - 2 x 1.62 x 2.55 x 10^6
v² = 8262000
v = 2874.37 m/s
v = 2.87 km/s
Thus, the initial speed should be 2.87 km/s.
Answer:
the intensity of the light after passing through the two polarizing filters is 4.11 units
Explanation:
Given the data in the question;
the intensity of an unpolarized light; I₀ = 25.0 units
when the unpolarized light passes through the first polarizer, its intensity reduces to half of its initial value;
⇒ I₁ = I₀/2 = 25/2 = 12.5 units
the angle between the transmission axes of two polarizers is;
∅ = 55° - 0° = 55°
The intensity of the light after passing through two polarizing filters will be;
I₂ = I₁cos²∅
we substitute
I₂ = 12.5 × cos²(55)
I₂ = 12.5 × 0.3289899
I₂ = 4.11 units
Therefore, the intensity of the light after passing through the two polarizing filters is 4.11 units
The players acceleration is 3.33 m/s/s
Acceleration= Velocity/Time
A =10/3
