Answer
given,
frequency from Police car= 1240 Hz
frequency of sound after return = 1275 Hz
Calculating the speed of the car = ?
Using Doppler's effect formula
Frequency received by the other car
..........(1)
u is the speed of sound = 340 m/s
v is the speed of the car
Frequency of the police car received

now, inserting the value of equation (1)


1.02822(340 - v) = 340 + v
2.02822 v = 340 x 0.028822
2.02822 v = 9.799
v = 4.83 m/s
hence, the speed of the car is equal to v = 4.83 m/s
The velocity equation is 
Known facts:
- t = 3.83s
- a= -3.04
- intial velocity = 0
Plug into equation known quantities:

Thus the final velocity is -11.6432m/s
Hope that helps!
Answer:
The object has 2 meter length. This means the length is any quantity with a dimension distance. The definition of the length is how long something is or amount of space. In the given data it is stated that, the object is something that has a length of 2 meter.
<em>Let's take examples to understand. </em>
For example a thread or a table is an object which has a total length of 2 meters.
Another example is something we are measuring it gives us a result of 2 meters of length by using a meter scale or meter tape.
Length is a measure of distance and it is a fundamental quantity. Meter is a international system of units (SI units).
Answer:
alkaline earth metals
Group 2 metals, the alkaline earth metals, have 2 valence electrons, and thus form M2+ ions. The halogens, Group 17 , reach a full valence shell upon reduction, and thus form X− ions
Explanation:
A scientific theory is different from a hypothesis because a theory is a educated guess that is being worked on and proven correct and a hypothesis is a educated guess it is a guess that needs to be proven.