Answer:



Explanation:
By analyzing the torque on the wheel we get:
Solving for T: 
On the object:
Replacing our previous value for T:

The relation between angular and linear acceleration is:

So,

Solving for α:

The linear acceleration will be:

And finally, the tension will be:

These are the values of all the variables: α, a, T
The answer would be:
C. An unbalanced force has acted on the vehicle.
The presence of an unbalanced force will accelerate an object, the second law of motion dictates this (Although not explicitly). Lets knock out the rest of the choices.
If a balance force acted on the vehicle, then the vehicle would be at rest. The mass of the vehicle did not change (Unless it falls apart, which I doubt). The direction of the vehicle does not change and it will only do so if another force and a stronger one at that will counteract the current net force acting on the vehicle.
Hope you got your answer here, although you did not ask for an explanation, maybe this will help you figure some of the other questions you have on your own.
Answer:
I think u are traeling at speed of light and not ur friend
Explanation:
Answer:
a) 9 - 1.2 = 7.8 N
b) Since the force exerted by the box is it's weight, it acts in a downward direction. So the box will exert a force downward (perpendicular to the horizontal surface).
Explanation:
A 9N block would exert 9N of normal force on the horizontal plane under normal conditions. But in this case, we have a spring taking away some of the force by applying an upward force on the box.
So the force exerted by the box on the surface would now be:
a) 9 - 1.2 = 7.8 N
b) Since the force exerted by the box is it's weight, it acts in a downward direction. So the box will exert a force downward (perpendicular to the horizontal surface).