Answer:
Average speed = 13.5 m/s
Explanation:
Since the car is running at a speed of 27 m/s and it stops after 3 seconds by applying the brake. Therefore, the initial speed of the 27 m/s and final speed is 0.
Use below formula to find the average speed :
Average speed = (Initial speed + final speed ) / 2
Average speed = (27 + 0 ) / 2
Average speed = 13.5 m/s
Answer:
Elastically
Explanation:
A rock that has deformed Elastically under stress keeps its new shape when the stress is released.
In elastic deformation the original shape of the object is regained when the stress is removed. Whereas in plastic deformation the original shape is parmanently deformed with the application of stress.
Answer: By 47
Explanation: subtract 310 and 263
To solve this problem it is necessary to apply the concepts related to Dopler's Law. Dopler describes the change in frequency of a wave in relation to that of an observer who is in motion relative to the Source of the Wave.
It can be described as

c = Propagation speed of waves in the medium
= Speed of the receiver relative to the medium
= Speed of the source relative to the medium
Frequency emited by the source
The sign depends on whether the receiver or the source approach or move away from each other.
Our values are given by,
Velocity of car
velocity of motor
Velocity of sound
Frequency emited by the source
Replacing we have that



Therefore the frequency that hear the motorcyclist is 601.7Hz