The California Science Center has an exhibit where on one end of the bar, they have a 500.0 kg pickup truck and on the other, students can add masses to raise the car. If the beam is 40.0 m long and the car is 5.00 meters from the fulcrum, what is the minimum mass required to balance the truck?

the bal will not change its velocity.

the answer is b, have negligible mass

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.