Answer and explanation:
When you are changing a car tire, the most important thing is to keep the total diameter as equal as possible.
The total car tire diameter can be calculated as:

The profile of this tire is 75 (the higher/taller relation), therefore a 5 percent lower profile would be:
pr=0.95·75=71.25
The problem is that the profiles are normalized and the nearest profile available is 70.
If we take a theorical tire with a profile of 71.25:

The theorical tire size should be 205/71 R15.
If we look for a real tire size, we should look for a tire with a diameter nearest to 26.5'' and a profile of 70.
The best option for real tire size is: Tire 225/70 R14 (wheel diameter of 26.4'') or 205/70 R15 (wheel diameter of 26.3'').
From the law of Galileo Galilei :v²=v₀²+2ad we take the speed
v²=0+2*4.90*200=1960=>v=√1960=44.27 m/s
Answer:
a) 2.933 m
b) 4.534 m
Explanation:
We're given the equation
v(t) = -0.4t² + 2t
If we're to find the distance, then we'd have to integrate the velocity, since integration of velocity gives distance, just as differentiation of distance gives velocity.
See attachment for the calculations
The conclusion of the attachment will be
7.467 - 2.933 and that is 4.534 m
Thus, The distance it travels in the second 2 sec is 4.534 m
Answer:
Change in electric potential energy ∆E = 365.72 kJ
Explanation:
Electric potential energy can be defined mathematically as:
E = kq1q2/r ....1
k = coulomb's constant = 9.0×10^9 N m^2/C^2
q1 = charge 1 = -2.1C
q2 = charge 2 = -5.0C
∆r = change in distance between the charges
r1 = 420km = 420000m
r2 = 160km = 160000m
From equation 1
∆E = kq1q2 (1/r2 -1/r1) ......2
Substituting the given values
∆E = 9.0×10^9 × -2.1 ×-5.0(1/160000 - 1/420000)
∆E = 94.5 × 10^9 (3.87 × 10^-6) J
∆E = 365.72 × 10^3 J
∆E = 365.72 kJ