The answer is either C or D..
Subtract the total mass of the tank and water by the mass of the empty tank. That will yield the mass of the water.
51.8 - 3.64 = 48.16.
Your answer is 48.16 kg
Mass of Tracey M1 = 32 kg
Mass of Jonas M2 = 45 kg
Initially both were at rest
so V1i = V2i =0
after pushing each other Jonas speed V2f = 0.80 m/s
we need to find out final speed of Tracy
Here we can use momentum conservation as no external force is acting here
M1V1i + M2V2i = M1V1f + M2V2f
32(0) + 45(0) = 32 V1f + 45(0.80)
0 = 32 V1f + 36
-36 = 32 V1f
V1f = - 1.125 m/s
negative sign shows that Tracy will move opposite to the Jonas
so answer in two significant figure would be
V1f = 1.1 m/s
