How is this description of a synapse different from the neuromuscular junction? For Anatomy and physiology

Ingrid wrote the hypothesis below. if the temperature of a liquid increases, the density of the liquid decreases because the particles move farther apart. what are the variables in her hypothesis?

Ablock of mass m = 2.5 kg is attached to a spring with spring constant k = 790 n/m. it is initially at rest on an inclined plane that is at an angle of 28 degrees with respect to the horizontal, and the coefficient of kinetic friction between the block and the plane is k = 0.14. in the initial position, where the spring is compressed by a distance of a = 0.18 m, the mass is at its lowest position and the spring is compressed the maximum amount. take the initial gravitational energy of the block as zero. b) if the spring pushes the block up the incline, what distance, l, in meters will the block travel before coming to rest? the spring remains attached to both the block and the fixed wall throughout its motion.

Calculate the mass of an object that has a momentum of 100kg x m/sec and velocity of 4 m/sec