Answer:
Average speed = 1.2 m/s
Average velocity = 0.4 m/s
Explanation:
Average speed = total distance/total time
Average speed = (40 + 20)/(40 + 10)
Average speed = 60/50
Average speed = 1.2 m/s
Average velocity = displacement/time
Now, she ran 40 m south and ran 20 m back north which is in the direction of where she began the journey.
Thus;
Displacement = 40 - 20 = 20 m
Average velocity = 20/50 = 0.4 m/s
Answer:
A ) 1000 m.
Explanation:
Here initial velocity u = 100 m /s
Final velocity v = 0
Acceleration a = -5 ms⁻²
Distance travelled = S
v² = u² + 2aS
0 = (100)² -2 x 5 S
S = 10000/ 10
=1000 m.
Answer:
Therefore,
The frequency heard by the engineer on train 1
Explanation:
Given:
Two trains on separate tracks move toward each other
For Train 1 Velocity of the observer,
For Train 2 Velocity of the Source,
Frequency of Source,
To Find:
Frequency of Observer,
(frequency heard by the engineer on train 1)
Solution:
Here we can use the Doppler effect equation to calculate both the velocity of the source 
and observer 
, the original frequency of the sound waves 
and the observed frequency of the sound waves 
,
The Equation is
Where,
v = velocity of sound in air = 343 m/s
Substituting the values we get
Therefore,
The frequency heard by the engineer on train 1
The pitch of a sound come from the frequency of the soundwave, soundwaves that have bigger frequencies sound with a high pitch and soundwaves with less frequencie have low pitch.
