A 3,000-kg railway car is traveling on a level track with a velocity of 8.0 m/s to the right when it collides head-on with another railway car of mass 5,000 kg that is traveling with a velocity equal to 4.0 m/s to the left. When the two cars collide, they couple together via internal hooks that are attached to the colliding faces of each car. What is the velocity of the tandem of cars after the collision

Distance covered, s = 8ft - 4ft = 4 ftinitial velocity, u = 34 ft/sthe acrobat is moving upwards and therefore, a = -g = -9.81 m/s^2 = 32.19 ft/s^2applying equation of motion; s = ut -1/2gt^2then,4 = 34t -1/2*32.19t^24 = 34t - 16.095t^2rearranging; -16.095t^2 + 34t - 4 = 0solving the quadratic equation; t = {-34 +/- sqrt [34^2 - 4(-16.)]}/2(-16.095) = 1.06 +/- 0.93 = 0.13 or 1.99the acrobat will take 0.13 seconds to be at 8 ft above the ground. additionally, once at the maximum height, the acrobat will move down and be at the same spot (that is height) after 1.99 seconds moving down.

You need to calculate the string in between two masses

120v is the answer i am positive tell me if this was correct