A block of mass m = 3.7 kg slides from left to right across a frictionless surface withra speed v; - 7.4 m/s. It collides in a perfectly elastic collision with a second block of mass M that is at rest. After the collision, the 3.7-kg block reverses direction, and its new speed is vf 2.2 m/s. What is M?

8.9 kg
6.8 kg
5.2 kg
7.5 kg

Rank the six combinations of electric charges on the basis of the electric force acting on q1. define forces pointing to the right as positive and forces pointing to the left as negative. rank positive forces as larger than negative forces. q1,q2,q3 = positive(+) q1 = + q2 = + q3 = - q1 = + q2= - q3= + q1= - q2= + q3= + q1= + q2= - q3= - q1,q2,q3 = negative