The slope of a speed-time graph is the acceleration represented by the graph.
All other parts of this question refer to a lab experiment or exercise
where I was not present, but Zeesam16 was. Therefore I have no data
with which to answer the rest of the question, and hope that Zeesam can
handle it.
Answer:

Explanation:
We can calculate the acceleration experimented by the passenger using the formula
, taking the initial direction of movement as the positive direction and considering it comes to a rest:

Then we use Newton's 2nd Law to calculate the force the passenger of mass m experimented to have this acceleration:

Which for our values is:

Answer: 33 mm
Explanation:
Given
Diameter of the tank, d = 9 m, so that, radius = d/2 = 9/2 = 4.5 m
Internal pressure of gas, P(i) = 1.5 MPa
Yield strength of steel, P(y) = 340 MPa
Factor of safety = 0.3
Allowable stress = 340 * 0.3 = 102 MPa
σ = pr / 2t, where
σ = allowable stress
p = internal pressure
r = radius of the tank
t = minimum wall thickness
t = pr / 2σ
t = 1.5*10^6 * 4.5 / 2 * 102*10^6
t = 0.033 m
t = 33 mm
The minimum thickness of the wall required is therefore, 33 mm
Answer:
Distance of 400m.
Explanation:
Use your kinematics equation to solve for distance (we can use kinematics b/c acceleration is constant).
d = (initial velocity x time) + 1/2 at^2
d = (20 x 10) + 1/2 (4) (10)^2
d = 200 + 200
d = 400 m