Answer:

Explanation:
m = Mass of object = 
mg = Weight of object = 20 N
g = Acceleration due to gravity = 
v = Final velocity = 15 m/s
u = Initial velocity = 0
d = Distance moved by the object = 150 m
= Angle of slope = 
f = Force of friction
fd = Work done against friction
The force balance of the system is

The work done against friction is
.
Well I think B hope this helps
Hello
It is called lightning. Lightning in a storm occurs when there are two regions (it can be cloud-cloud or cloud-ground), one with a strong excess of positive charges and the other one with a strong excess of negative charges. The two types of charge attract each other, and then a sudden flow of charges from one region to the other occurs, which is called lightning.
If your engine is not at the right temprature, usually when it is too hot.
Answer:
The vector sum of all forces acting on it is zero, its at equilibrium.
Explanation:
The bag of marbles hanging on a spring scale applies its weight downwards, which was counterbalanced by the reaction from the spring scale (obeying the Newton's third law of motion). And since no external forces are applied to the system, thus the equilibrium of the system.
If the weight of the bag is greater than the reaction from the spring scale, the scale breaks and the system would not be balanced.