Answer:

Explanation:
given,
velocity of particle 1 = 0.741 c to left
velocity of second particle = 0.543 c to right
relative velocity between the particle = ?
for the relative velocity calculation we have formula

u_x = 0.543 c
v_x = - 0.741 c




Relative velocity of the particle is 
Passive transport occurs thanks to diffusion, diffusion is the reason passive transport is able to travel throughout the cell membrane.
Answer:
D, using a spring scale to exert a force on the block. Measure the acceleration of the block and the applied force
Explanation:
For this you would use the net force equation acceleration=net force * mass however you will want to isolate mass so it would be acceleration/ net force to get mass. Then process of elimination comes to play.
2,450 Joules, kinetic energy is 1/2 mass x velocity squared.