Object a has of mass 7.20 kilograms, and object b has a mass of 5.75 kilograms. the two objects move along a straight line toward each other with velocities +2.00 meters/second and -1.30 meters/second respectively. what is the total kinetic energy of the objects after the collision, if the collision is perfectly elastic? a. 19.3 joules b. 21.9 joules c. 38.5 joules d. 43.0 joules e. 50.8 joules

A.   19.3 joules

Explanation:

The collisions is perfectly elastic: this means that both total momentum and total kinetic energy are conserved after the collision.

Therefore, we can just calculate the total initial kinetic energy before the collision, and then say that it is equal to the total kinetic energy after the collision.

The kinetic energy of object A is:

The kinetic energy of object B is:

So, the total kinetic energy before (and after) the collision is

a small object of mass 3.66 g and charge -17.6 µc is suspended motionless above the ground when immersed in a uniform electric field perpendicular to the ground. what are the magnitude and direction of the electric field?

grav force prop 1/r squared 2r all squared is 4rsquared 1/4rsquared quartered