The compass magnet aligns itself with the earths magnetic field.
Answer:
The answer is given below
Explanation:
u is the initial velocity, v is the final velocity. Given that:

a)
The final velocity of cart 1 after collision is given as:

The final velocity of cart 2 after collision is given as:

b) Using the law of conservation of energy:

Answer:
Number of gallons =2 gallon
Explanation:
given data:
rate of gasoline ineurope = 5 euro per liter
total money to buy gasoline = 40 euro
total gasoline an american can buy in europe 
= 8 litres of gasoline
As given in the question 1 ltr is 1 quarts therefore
Total no. of quarts is 8 quarts
As from question 4 quarts is equal to one gallon, hence
Number of gallons
this is due to the existence of other forces called the strong nuclear forces that overcomes the repulsion forces between the protons and keeps the nucleons holding to each other also there is a type of energy that is called the nuclear binding energy and this energy also works on binding the components of the nucleus together