Answer:
Angle of incidence = 20°
Angle of reflection = 20°
Explanation:
Applying,
The first Law of Refraction: The incident ray, the reflected ray and the normal at the point of incidence all lies in the plane.
From the diagram,
Angle of incidence = 90-70
Angle of incidence = 20°
From the law of reflection,
Angle of incidence = Angle of reflection
Therefore,
Angle of reflection = 20°
Answer:
Explanation:
We shall apply concept of Doppler's effect of apparent frequency to this problem . Here observer is moving sometimes towards and sometimes away from the source . When observer moves towards the source , apparent frequency is more than real frequency and when the observer moves away from the source , apparent frequency is less than real frequency . The apparent frequency depends upon velocity of observer . The formula for apparent frequency when observer is going away is as follows .
f = f₀ ( V - v₀ ) / V , f is apparent , f₀ is real frequency , V is velocity of sound and v is velocity of observer .
f will be lowest when v₀ is highest .
velocity of observer is highest when he is at the equilibrium position or at middle point .
So apparent frequency is lowest when observer is at the middle point and going away from the source while swinging to and from before the source of sound .
Answer:
Option B. magnitude of displacement of a sound pressure wave
Explanation:
Amplitude is simply the maximum displacement of a wave from its mean position.
Answer:
6.86 N
Explanation:
Applying,
F = mg............... Equation 1
Where F = Force exerted by gravity on the mass, m = mass, g = acceleration due to gravity
Note: The Force exerted by gravity on the mass is thesame as the weight of the body.
From the question,
Given: m = 700 g = (700/1000) = 0.7 kg
Constant: g = 9.8 m/s²
Substitute these values into equation 1
F = 9.8(0.7)
F = 6.86 N
Answer:
Fossil-fueled cars are still outnumbering the alternative and replacement-fueled cars because they are generally cost-effective and are efficient.
Explanation:
<em>Fossil fuels</em> are non-renewable energy that cannot be replenished. Although many people know how harmful using them can be to the environment, still, people continue to buy cars that are powered by it. This is because, <em>using fossil-fueled cars can help you save money</em> compared to using<em> replacement-fueled cars.</em><em> Its engines are also more powerful,</em> which means they can arrive at their destination in just a few minutes. <u>This makes it efficient.</u> The cost of maintaining a fossil-fueled car is less expensive compared to<em> replacement-fueled cars.</em> People are naturally keen when it comes to budgeting, thus, many people still buy cars powered by fossil fuels.
