A car has constant acceleration as it passes two checkpoints. The time taken between checkpoints is 4 s, and the car’s acceleration is 6 m/s2. If the car’s speed at the first checkpoint is 1 m/s, what is the speed at the second checkpoint?

Suppose that three astronomical objects, 1, 2, and 3 are observed to lie on a line, and the distance from object 1 to object 3 is d. object 1 has four times the mass of object 3, and seven times the mass of object 2. find the distance between objects 1 and 2 for which the net force on object 2 is zero.