Answer:

Explanation:
<u>Average Density
</u>
The density of an object of mass m and volume V is

If we know the density and the volume occupied by the object, the mass can be computed as

The tank can hold 20 L of gasoline when full. Converting to cubic meters

That's the volume of the gasoline it contains. Knowing the density of the gasoline, we get the mass of gasoline.

To know the total mass of both, we add the 2.5 kg of the tank

The volume of the tank is computed solving for V


The total volume is

The average density is


Answer:
The velocity is 
Explanation:
From the question we are told that
The first distance is 
The first speed is 
The second distance is 
The second speed is 
Generally the time taken for first distance is



The time taken for second distance is



The total time is mathematically represented as

=> 
=> 
Generally the constant velocity that would let her finish at the same time is mathematically represented as

=> 
=> 
Answer: When an ambulance passes with its siren blaring, you hear the pitch of the siren change: as it approaches, the siren’s pitch sounds higher than when it is moving away from you. This change is a common physical demonstration of the Doppler effect.
Explanation:
Answer:
when a element of 1 group take part in reaction, its atom looses outer electron and form positively charged ions called Cation.
Explanation:
There was a supercontinent called Pangea