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: Fr = 26.53 N
Explanation: The constant force exerted on the block by the surface is the frictional force.
This frictional force is as a result of interaction between the body and the surface.
According to newton's second law of motion,
F - Fr = ma
F=applied force
Fr = magnitude of frictional force
m = mass of object = 12kg
a = acceleration of object = 3.2m/s²
The applied force (F= 75 N) is inclined at an angle of 30° to the horizontal thus making it have 2 components of forces given below
Fx = 75 * cos 30 = 64.95 N (horizontal component)
Fy = 75 * sin 30 = 37.5 N ( vertical motion)
The body moves across the surface, hence the horizontal component of force is responsible for motion.
F = 64.95 N
By substituting the parameters, we have that
64.96 - Fr = 12 * 3.2
64.96 - Fr = 38.4
Fr = 64.96 - 38.4
Fr = 26.53 N
Use energy conservation to calculate the speed!
Total kinetic energy before collision = total kinetic energy after the collision.
Answer:
C voltage
Explanation:
Voltage is the change in electric potential so basically current flows from high potential to low potential due to voltage.