Answer:
The frequency heard by the motorist is 4313.2 Hz.
Explanation:
let f1 be the frequency emited by the police car and f2 be the frequency heard by the motorist, let v1 be the speed of the police car and v2 be the speed of the motorist and v = 343 m/s be the speed of sound.
because the police car is moving towards the motorist at a higher speed, then the motorist will hear a increasing frequency and according to Dopper effect, that frequency is given by:
f1 = [(v + v2/(v - v1))]×(f2)
= [( 343 + 30)/(343 - 36)]×(3550)
= 4313.2 Hz
Therefore, the frequency heard by the motorist is 4313.2 Hz.
Answer:
D. The moon is closer to Earth than the sun.
Explanation:
Tides are formed as a consequence of the differentiation of gravity due to the moon across to the Earth sphere.
Since gravity variate with the distance:
(1)
Where m1 and m2 are the masses of the two objects that are interacting and r is the distance
For example, see the image below, point A is closer to the moon than point b and at the same time the center of mass of the Earth will feel more attracted to the moon than point B. Therefore, that creates a tidal bulge in point A and point B.
The Sun tidal force contributes to the tidal force of the moon over the earth making high tides higher and low tides lower.
However, even when the sun is more massive than the moon, it is farther away from the Earth than the moon. So, it is clear by equation 1 that the moon's gravity has a greater effect on Earth's oceans than the sun's gravity.
The answer is going to be magnetic domain
Answer: Part(a)=0.041 secs, Part(b)=0.041 secs
Explanation: Firstly we assume that only the gravitational acceleration is acting on the basket ball player i.e. there is no air friction
now we know that
a=-9.81 m/s^2 ( negative because it is pulling the player downwards)
we also know that
s=76 cm= 0.76 m ( maximum s)
using kinetic equation

where v is final velocity which is zero at max height and u is it initial
hence


now we can find time in the 15 cm ascent


using quadratic formula

t=0.0409 sec
the answer for the part b will be the same
To find the answer for the part b we can find the velocity at 15 cm height similarly using

where s=0.76-0.15
as the player has traveled the above distance to reach 15cm to the bottom


when the player reaches the bottom it has the same velocity with which it started which is 3.861
hence the time required to reach the bottom 15cm is

t=0.0409