The average time that it takes for the car to travel the first 0.25m is 2.23 s
The average time that it takes for the car to travel the first 0.25 m is given by:

The average time to travel just between 0.25 m and 0.50 m is 0.90 s
First of all, we need to calculate the time the car takes in each trial to travel between 0.25 m and 0.50 m:

Then, the average time can be calculated as

Given the time taken to travel the second 0.25 m section, the velocity would be 0.28 m/s
The velocity of the car while travelling the second 0.25 m section is equal to the distance covered (0.25 m) divided by the average time (0.90 s):

Answer:
B. blocks 2 & 3.
Explanation:
Block 1 has equal & opposite forces acting on it.
Block 2 has 5N on one side, 3N on the other. It will move in the direction the 5N of force is pushing.
Block 3 has no opposing force.
Answer:
P V = n R T ideal gas equation
P2 V2 / P1 V1 = T2 / T1
V2 / V1 = T2 / T1 * P1 / P2 = T2 P1 / (T1 P2)
V2 / V1 = (1.17 T1) / T1 * (P1 / .22 P1) assuming absolute temp as 1.17 P1
V2 / V1 = 1.17 / .22 = 5.32
V = 4/3 pi R^3 = 4/3 pi (D/2)^3 = 4/3 pi D^3 / 8 = pi D^3 / 6
V2 / V1 = D2^3 / D1^3
D2 = (V2 / V1 * D1^3)^1/3
D2 = 5.32^1/3 * D = 1.75 D (D1 = D)