Answer:
3.44 W/m²
1.134 J
Explanation:
E₀ = Intensity of electric field = 50.9 V/m
I = Intensity of electromagnetic wave
Intensity of electromagnetic wave is given as
I = (0.5) ε₀ E₀² c
I = (0.5) (8.85 x 10⁻¹²) (50.9)² (3 x 10⁸)
I = 3.44 W/m²
A = Area = 0.0277 m²
t = time interval = 11.9 s
Amount of energy is given as
U = I A t
U = (3.44) (0.0277) (11.9)
U = 1.134 J
No
Explanation:
Average speed of car = 5m/s
Distance run by dog = 20m
Time taken = 5s
problem;
does the dog catches the car = ?
Solution;
let us determine speed of the dog;
Speed = 
= 4m/s
The average speed of the car is 5m/s
Average speed of the dog is 4m/s
The dog is slower than the car and it will not catch the car at this rate.
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Average speed brainly.com/question/5063905
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Answer:
-20.0 m/s and 30.0 m/s
Explanation:
Momentum is conserved:
m (30.0) + m (-20.0) = m v₁ + m v₂
30.0 − 20.0 = v₁ + v₂
10.0 = v₁ + v₂
Since the collision is perfectly elastic, energy is also conserved. Since there's no rotational energy or work done by friction, the initial kinetic energy equals the final kinetic energy.
½ m (30.0)² + ½ m (-20.0)² = ½ mv₁² + ½ mv₂²
(30.0)² + (-20.0)² = v₁² + v₂²
1300 = v₁² + v₂²
We now have two equations and two variables. Solve the system of equations using substitution:
1300 = v₁² + (10 − v₁)²
1300 = v₁² + 100 − 20v₁ + v₁²
0 = 2v₁² − 20v₁ − 1200
0 = v₁² − 10v₁ − 600
0 = (v₁ + 20) (v₁ − 30)
v₁ = -20, 30
If v₁ = -20, v₂ = 30.
If v₁ = 30, v₂ = -20.
So either way, the final velocities are -20.0 m/s and 30.0 m/s.
Answer:
3. The driving frequency is not matched to the natural frequency of the oscillatory system.
Explanation:
- It is the condition of resonance when the one body that oscillates with a maximum amplitude when the frequency of the applied force is equal to the natural frequency of the body.
- Every body has its own natural frequency.
- Here the driving force may be more or less but we are sure that it is not equal to the natural frequency of oscillatory system. Hence the force is not in resonance with the oscillatory system.
