I would say the answer to your question is A Ferris wheel turning at a constant speed. The reasoning behind this answer is the fact that traveling in a constant direction at a constant speed is not accelerating. The Ferris wheel is the only option that fits this description. The last option would be incorrect due to independent causes such as speed limit changes as well as turns and stops on the highway.
Answer:
B) the change in momentum
Explanation:
Impulse is defined as the product between the force exerted on an object (F) and the contact time (
)
Using Newton's second law (F = ma), we can rewrite the force as product of mass (m) and acceleration (a):
However, the acceleration is the ratio between the change in velocity (
) and the contact time (): 
, so the previous equation becomes
And by simplifying ,
which corresponds to the change in momentum of the object.
Answer:
a) x = ⅔ d
, b) the charge must be negative, c) Q
Explanation:
a) In this exercise the force is electric between the charges, we are asked that the system of the three charges is in equilibrium, we use Newton's second law. Balance is on the third load that we are placing
∑ F = 0
-F₁₂ + F₂₃ = 0
F₁₂ = F₂₃
let's replace the values
k Q Q / r₁₂² = k Q 4Q / r₂₃²
Q² / r₁₂² = 4 Q² / r₂₃²
suppose charge 3 is placed at point x
r₁₂ = x
r₂₃ = d-x
we substitute
1 / x² = 4 / (d-x) 2
1 / x = 2 / (d-x)
x = 2 (x-d)
x = 2x -2d
3x = 2d
x = ⅔ d
b) The sign of the charge must be negative, to have an attractive charge on the two initial charges
c) Q
Answer:
Final velocity will be 314.6 m/sec
Distance traveled = 1314.24 m
Explanation:
We have given initial velocity u = 233 m/sec
Acceleration 
Time t = 4.8 sec
From first equation of motion 
, here v is final velocity, u is initial velocity and t is time
So 
Now we have to find distance traveled
From second equation of motion
So distance traveled in given time will be 1314.24 m
Explanation:
They probably put "rolls without slipping" in there to indicate that there is no loss in friction; or that the friction is constant throughout the movement of the disk. So it's more of a contingency part of the explanation of the problem.
(Remember how earlier on in Physics lessons, we see "ignore friction" written into problems; it just removes the "What about [ ]?" question for anyone who might ask.)
In this case, you can't ignore friction because the disk wouldn't roll without it.
As far as friction producing a torque... I would say that friction is a result of the torque in this case. And because the point of contact is, presumably, the ground, the friction is tangential to the disk. Meaning the friction is linear and has no angular component.
(You could probably argue that by Newton's 3rd Law there should be some opposing torque, but I think that's outside of the scope of this problem.)
Hopefully this helps clear up the misunderstanding for you.
