A1200-kg car traveling initially with a speed of 25.0 m/s in an easterly direction crashes into the rear end of a 9,000-kg truck moving in the same direction at 20.0 m/s. the velocity of the car right after the collision is 18.0 m/s to the east. a. what is the velocity of the truck right after the collision? b. how much mechanical energy is lost in the collision? account for this loss in energy.

Explanation:

Given

mass of car

initial speed of car

Final Speed of car

Mass of Truck

initial speed of Truck

Let be the speed of truck after collision

Conserving momentum

(b)Initial Kinetic Energy of car

Initial Kinetic Energy of Truck

Final Kinetic Energy of car

Final Kinetic Energy of Truck

Change in kinetic Energy=Initial Kinetic Energy-Final kinetic Energy

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west

causes

fossil fuels burn

cities become more industrialized

human population grows worldwide