Answer:b
Explanation:
Given
mass of first cart 
mass of second cart 
velocity of first cart 
conserving momentum



Initial kinetic Energy 


Final Kinetic Energy


Ratio of initial Kinetic Energy to the Final Kinetic Energy

Given that,
Mass of the stone, m = 400 g = 0.4 kg
Initial speed, u = 20 m/s
It is climbed to a height of 12 m.
To find,
The work done by the resistance force.
Solution,
Let v is the final speed. It can be calculated by using the conservation of energy.

Work done is equal to the change in kinetic energy. It can be given as follows :

So, the required work done is 32.99 J.
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:
F = -4567.40 N
Explanation:
Given that,
The power developed by the engine, P = 196 hp
1 hp = 746 W
196 hp = 146157 W
Speed of the car, v = 32 m/s
Let F is the total friction force acting on the car. The product of force and velocity is called the power developed by the engine. It is given by :



F = -4567.40 N
So, the total frictional force acting on the car is 4567.40 N. Hence, this is the required solution.