All describe an objects motion except : mass
Because air does not exist in space
For plato users, I just took the test and D is your correct answer!
Answer:
(a) Charge density σ=6.6375×10²nC/m²
(b) Total charge Q=1.47×10²nC
Explanation:
Given Data
A=47.0 cm =0.47 m
Electric field E=75.0 kN/C
To find
(a) Charge density σ
(b)Total Charge Q
Solution
For (a) charge density σ
From Gauss Law we know that
Φ=Q/ε₀.......eq(i)
Where
Φ is electric flux
Q is charge
ε₀ is permittivity of space
And from the definition of flux
Φ = EA
The flux is electric field passing perpendicularly through the surface
Put the this Φ in equation(i)
EA
=Q/ε₀
where Q(charge)=σA
EA=(σA)/ε₀
E=σ/ε₀
σ=ε₀E

σ=6.6375×10²nC/m²
For (b) total charge Q
Q=σA

The only thing acting as the roller coaster gets to the bottom is gravity thus
acceleration is 9.81
so u use the formula
vf^2 = vi^2 + 2abetaD
thus
distance = vf^2 - vi^2 divided by 2a
so 26^2 - 0^2 divided by 2(9.81m/s)
equals 676 divided by 2(9.81m/s)
= 34.45463812m
then use the appropriate 3 sig digs
so 34.5m
hopes this helps