Sa steel ball with mass =5.21 g is moving horizontally with speed =412 m/s when it strikes a block of hardened steel with mass =14.8 kg (initially at rest). the ball bounces off the block in a perfectly elastic collision. (a) what is the speed of the block immediately after the collision?

Two charged particles, q1 and q2, are located on the x-axis, with q1 at the origin and q2 initially at x1 = 12.2 mm. in this configuration, q1 exerts a repulsive force of 2.62 µn on q2. particle q2 is then moved to x2 = 18.0 mm. what is the force (magnitude and direction) that q2 exerts on q1 at this new location? (give the magnitude in µn.)