The Doppler effect occurs when a source of sound or light
moves either toward or away from the observer.
Part a)
At t = 0 the position of the object is given as

At t = 2

so displacement of the object is given as

so average speed is given as

Part b)
instantaneous speed is given by


now at t= 0

at t = 1


at t = 2

Part c)
Average acceleration is given as



Part d)
Now for instantaneous acceleration
As we know that

at t = 0

at t = 1

now we have

At t = 2 we have



<em>so above is the instantaneous accelerations</em>
Answer:
0.64 m
Explanation:
The first thing is calculate the center of mass of the system.

now multiplying every coordinate x by the mass of each object (romeo, juliet and the boat) and dividing all by the total mass taking by reference the position of juliet.

X_cm = 1.4589 m
When the forces involved are internals, the center of mass don't change
After the movement the center of mass remains in the same distance from the shore, but change relative to the rear of the boat.

X_cm= 2.10 m
this displacement is how the boat move toward the shore.
2.10-1.46= 0.64 m
Answer:
The answer an be the option A.
Explanation:
Because radioactive substances have atomic number greater than 82.