Answer:
changing the direction in which a force is exerted
The most common metals used for permanent magnets are iron, nickel, cobalt and some alloys of rare earth metals
Answer:
According to the right-hand rule, the magnetic field is into the page.
Explanation:
According to the right-hand rule, the magnetic field is into the page. According to this rule, if the middle finger points in the direction of initial motion of the charge as it enters the magnetic field to the right, and point the thumb and index finer perpendicular to each other and the middle finer perpendicular to the index finer. We then point the middle finger to the right in the direction of motion of the proton. If we are to have a clockwise force on the proton in the plane of the page, the thumb must point parallel to the page, downwards towards the south. The direction of the index finger is thus the direction of the magnetic field, and this is into the page.
Answer: 394 Hz
Explanation: this is a question under Doppler effect.
The mathematical equation that defines a Doppler effect is given below as
fo = {c+ vo/ c - vs} × f
Where fo = frequency observed =?
c = speed of sound = 345 m/s
vo = velocity of observer relative to source = 9.5m/s
vs = velocity of source relative to observer = - 9.5 m/s ( the negative sign is as a result of the fact that the observer and the source are moving in opposite direction to each other)
f = frequency of sound by source = 394 Hz.
By substituting the parameters, we have that
fo = {345 + 9.5/ 345 - (-9.5)} × 394
fo = (345 +9.5/ 345 + 9.5) × 394
fo = (354.5/354.5) × 394
fo = 1 × 394 = 394 Hz