Answer:
The football leaves with the velocity, u = 15.68 m/s
Explanation:
Given data,
The football bounces back up off the ground and is airborne for, t = 3.2 s
Let the football bounces back up off the ground in the vertical direction
The formula for time of flight is given by,
                               t = 2u /g
∴                             u = gt / 2
Substituting the values,
                                u = 9.8 x 3.2 / 2
                                 u = 15.68 m/s
Hence, the football leaves with the velocity, u = 15.68 m/s
 
        
             
        
        
        
Momentum is conserved after the collision 
Momentum of 2 Kg before collision = 2 * 3 = 6
Momentum of 4 kg  before collision = 4 * -3 = -12
so 6 + -12 = 2 * -4 + 4 *x   where x is velocity of 4kg marble.
4x - 8 = -6
4x = 2
x = 0.5 
Velocity of 4 kg marble is 0.5 m/s after collision
The 2 kg marble will move in the opposite direction to which it was moving before the collision.
        
             
        
        
        
Seatbelt- strapped in egg
air bag- cushion around the egg
brakes- parachute(bag that helps the egg go down slower)
        
             
        
        
        
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
 
        
             
        
        
        
Answer:
They are called beneficial mutations. They lead to new versions of proteins that help organisms adapt to changes in their environment. Beneficial mutations are essential for evolution to occur. They increase an organism's changes of surviving or reproducing, so they are likely to become more common over time.
Explanation: