Forehead, Feet and Elbows, if the person is perfect health condition.
To solve this problem we will apply the concepts related to the Doppler effect. The Doppler effect is the change in the perceived frequency of any wave movement when the emitter, or focus of waves, and the receiver, or observer, move relative to each other. Mathematically it can be described as,

Here,
= Frequency of Source
= Speed of sound
f = Frequency heard before slowing down
f' = Frequency heard after slowing down
v = Speed of the train before slowing down
So if the speed of the train after slowing down will be v/2, we can do a system equation of 2x2 at the two moments, then,
The first equation is,



Now the second expression will be,



Dividing the two expression we have,

Solving for v, we have,

Therefore the speed of the train before and after slowing down is 22.12m/s
Answer:
The formula for speed is speed=<u>d</u><u>i</u><u>s</u><u>t</u><u>a</u><u>n</u><u>c</u><u>e</u>
time
Explanation:
to work out what the units are for speed,you need to know the units for distance and time.In this example,distance is in metres(m) and time is in seconds (s) , so the units for speed is metre per second (m/s).
terminal velocity ... greater speed ... acc is 10m/s/s
Answer:
D
Explanation:
<em>The correct answer would be in the axle of the wheels while you ride your bicycle.</em>
Options A, B, and C requires that the forces of friction is increased in order to have more control.
However, option D requires that there is a minimal frictional force in the axle of the wheels of a bicycle while riding so that a little effort would be required to keep the bicycle moving.
<u>The lesser the friction, the lower the effort that would be needed to keep the bicycle moving and vice versa.</u>