Answer:
The items here are describing either a condition in a later interacton or a protogalactic cloud. The results matching with spiral and elliptical galaxy are:
For spiral galaxy are options 6,3,2 and 5.
and for elliptical galaxy are options 4 and 1.
Explanation:
Here it is given that astrnomers suspect that types of galaxy can be affected both by the conditions which occurs due to protogalactic cloud and then from it forms the initial conditions and then by the later interactions with the other galaxies.
so, both types of galaxies are matched with their respective items given:
A. Spiral galaxy:
2. A galaxy collision results tostripping of gas.
3. The protogalactic cloud rotates in a very slow motion.
5. The density of protogalactic cloud is very high.
6. when the protogalactic cloud shrinks cloud forms very rapidly.
B. Elliptical galaxy:
1. The protogalactic cloud has high angular momentum.
4. Most of the protogalactic gases settles down into a disk.
Answer:
Explanation:
In the first case you can use the expression for the Doppler effect when the source is getting closer and getting away
( 1 )
( 2 )
f' = perceived frequency when the source is getting closer
f'' = perceived frequency when the source is getting away
f = source frequency
v = relative speed
vs = sound speed
by dividing (1) and (2) you have

but this is the relative velocity, you have that

a. hence, the speed of the police car is 102.5m/s
Electric field is defined as force per unit charge.
So it is given by

now we can find electric field by



So field strength is 0.75 N/C.