The most common metals used for permanent magnets are iron, nickel, cobalt and some alloys of rare earth metals
The perceived frequency when the fire truck is moving toward you and away from you will be 370 Hz and 329.59 Hz respectively.
<h3>What is the Doppler effect?</h3>
A sudden change in the frequency due to the distance between the objects and source is explained by the doppler effect.
As the source and observer travel toward each other, the frequency of sound, light, or other waves increases or decreases.
The perceived frequency when the fire truck is moving toward you;
The perceived frequency when the fire truck is moving away from you;
Hence, the perceived frequency when the fire truck in cases 1 and 2 will be 370 Hz and 329.59 Hz.
To learn more about the doppler effect refer to the link;
brainly.com/question/15318474
#SPJ1
Decelerate
<u>Explanation:</u>
If a charged object is moving against an electric force, the electric force would cause the charged object to decelerate. Rate of deceleration would depend on the amount of the charge the object posses and amount of the opposing electric force.
This could be understood by visualising a hypothetical situation where a charged object is moving against an electric force. Since the object is charged, it would exert a force in its direction of motion which would be opposed by the electric force, thus causing it to decelerate
675g/cm³ is the density of the liquid
Here we have given that
density of wood be ρ.
the volume of the block be V
The volume of the block =1/4 v
The volume of the immersed block (v) =V-1/4V=3/4V
We know the weight of the block = the weight of the water displaced by the submerged part of the block.
i.e. V x ρ x g
= 3/4 x900g/cm³
= 675g/cm³
Density is a measure of mass divided by the volume of an object. Defined as mass per unit volume. here from the above equation we have substituted the given value and we got the answer as 675g/cm³
Learn more about Density here brainly.com/question/1354972
#SPJ9
Increasing the separation distance between objects decreases the force of attraction or repulsion between the objects. And decreasing the separation distance between objects increases the force of attraction or repulsion between the objects. Electrical forces are extremely sensitive to distance.
