To practice problem-solving strategy 16.2 doppler effect. the sound source of a ship’s sonar system operates at a frequency of 22.0 khz . the speed of sound in water (assumed to be at a uniform 20∘c) is 1482 m/s . what is the difference in frequency between the directly radiated waves and the waves reflected from a whale traveling straight toward the ship at 4.95 m/s ? assume that the ship is at rest in the water. mastering physics g

147 Hz

Explanation:

First we need to know what frequency will the waves hitting the whale have respect of it.

The change in frequency is calculated with this equation:

However in this case, the wave is bouncing on the whale and coming back, so there is a double frequency shift (the difference is the same both times because the relative speeds between the two objects is the same both times)

Then:

The frequency shift is positive, it will have increased frequency.

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.

this would be about 43%