<span>As it is uniform circular motion therefore speed is constant. Therefore we can rule out option B. Also in circular motion the direction of velocity vector changes therefore velocity can't be constant. Therefore option B is incorrect as well. Also centripetal acceleration is always towards the center so option D is wrong as well.
That implies
option A is correct.</span>
Answer
given,
frequency from Police car= 1240 Hz
frequency of sound after return = 1275 Hz
Calculating the speed of the car = ?
Using Doppler's effect formula
Frequency received by the other car
..........(1)
u is the speed of sound = 340 m/s
v is the speed of the car
Frequency of the police car received

now, inserting the value of equation (1)


1.02822(340 - v) = 340 + v
2.02822 v = 340 x 0.028822
2.02822 v = 9.799
v = 4.83 m/s
hence, the speed of the car is equal to v = 4.83 m/s
Answer:
400 kilogram
Explanation:
Force exerted is directly proportional to the mass of an object.
F=ma where m is mass and a is acceleration. Taking uniform acceleration on all objects then the larger the mass the higher the force and vice versa. Theredore, among the masses given, 400 kilograms is the largest hence it exerts the largest force at the bottom
Answer:
Explanation:
1. We can find the temperature of each star using the Wien's Law. This law is given by:
(1)
So, the temperature of the first and the second star will be:


Now the relation between the absolute luminosity and apparent brightness is given:
(2)
Where:
- L is the absolute luminosity
- l is the apparent brightness
- r is the distance from us in light years
Now, we know that two stars have the same apparent brightness, in other words l₁ = l₂
If we use the equation (2) we have:

So the relative distance between both stars will be:
(3)
The Boltzmann Law says,
(4)
- σ is the Boltzmann constant
- A is the area
- T is the temperature
- L is the absolute luminosity
Let's put (4) in (3) for each star.

As we know both stars have the same size we can canceled out the areas.


I hope it helps!