Answer:
option (c)
Explanation:
According to the doppler's effect, the frequency of sound decreases.
If there is a relative motion between the source and the observer, the frequency of sound changes apparently.
the formula of the doppler effect is given by

where, f is the real frequency, v be the speed of sound, vo be the speed of the observer, here, the bus is the observer.
So, the value of f' < f
Decrease the amount of work done.
Answer:
learning and memory are very closely related concept . Learning is the acquisition of silk or knowledge, while memory is the expression of what you've acquired.Another difference is the speed with which the two things happen if you acquire the new skill or knowledge slowly and laboriously, that's learning
Answer:
Design 2
Explanation:
I had this same question
My answer:
"Design 2 is the well-designed one, because the air molecules are the most compact and could protect the individual better than 1,3,and no air bag."
Answer:
The official measurement unit for energy is the Joule (J). Among the most common units measuring energy mention should be made of the kilowatt/hour (kWh), used especially for electric energy (in fact it is used to calculate electricity bills).
Explanation: