Answer:
3rd order polynomial
Explanation:
Given that the increase in the order of the polynomial the error between the curve fit and measured data will decreases hence :
The polynomial order that is best to use is the 3rd order polynomial, this is because using a 3rd order polynomial will produce a less variance and a low Bias
The answer is C upwards at 20cm
Answer:
16.46 seconds.
13.46 seconds
2.67 m/s²
Explanation:
Acceleration = a = 1.35 m/s²
Final velocity = v = 80 km/h = 
Initial velocity = u = 0
Equation of motion

Time taken to accelerate to top speed is 16.46 seconds.
Acceleration = a = -1.65 m/s²
Initial velocity = u = 80 km/h= 
Final velocity = v = 0

Time taken to stop the train from top speed is 13.46 seconds
Initial velocity = u = 80 km/h= 
Time taken = t = 8.3 s
Final velocity = v = 0

Emergency deceleration is 2.67 m/s²
Hi there!
We can calculate linear momentum using the following:

p = linear momentum (kgm/s)
m = mass (kg)
v = velocity (m/s)
Calculate:

Now, we can relate force, time, and momentum with the following:

I = Impulse (kgm/s)
F = Force (N)
t = time (s)
Rearrange to solve for force:

The impulse is equal to the change in momentum. Since the car comes to a halt, all of its momentum is lost, so:

Solve:

**Negative force since the positive direction is towards the wall, and the negative direction is away from the wall.
Answer:
Explanation:
Please try to take a better photo as it is difficult to read.
For the first case, it is a small force to the right as there is a small velocity change.
For the second case, there is no force as there is no change in velocity
For the third case, it is a large (could be medium but photo is too blurry) force to the right as there is a large change in velocity.