Kinetic energy = 0.5 * m * v²
m mass
v velocity
If the velocity stays the same and the kinetic energy goes down by a factor of 2, the mass must go down by a factor of 2 also.
Collaboration in science is important because if only one scientist does an experiment, and gets a result, he/she could have messed. So this is where collaboration comes in. A few other scientists could try the experiment, and if they get the same answers, the result may be proven correct.
Hope this helped!
