Positive - Friction allows us to create heat in a desperate situation, like being lost in the woods. If we didn't have friction, we would probably freeze to death.
Negative - Friction can also cause unwanted fires, such as forest fires. If friction didn't exist, we wouldn't have these.
To solve this problem it is necessary to apply the concepts of Work. Work is understood as the force applied to travel a determined distance, in this case the height. The force in turn can be expressed by Newton's second law as the ratio between mass and gravity, as well

Where,
m = mass
h = height
g = Gravitational constant
When it ascends to the second floor it has traveled the energy necessary to climb a height, under this logic, until the 4 floor has traveled 3 times the height h of each of the floors therefore

Replacing in our equation we have to

The correct answer is 4.
Explanation:
The unit of work done is in Joules
Work done is a physical quantity that is defined as the force applied to move a body through a particular distance.
Work is only done when the force applied moves a body through a distance.
Work done = Force x distance
The maximum work is done when the force is parallel to the distance direction.
The minimum work is done when the force is at an angle of 90° to the distance direction.
So to solve this problem;
multiply the force applied by Zack and distance through which the bull was pulled.
Answer:
They measured their train using their handspan
Answer:
Explanation:
Givens
vi = 10 m/s
a = 1.5 m/s^2
d = 600 m
vf = ?
Formula
vf^2 = vi^2 + 2*a*d
Solution
vf^2 = 10^2 + 2*1.5 * 600
vf^2 = 100 + 1800
vf^2 = 1900
sqrt(vf^2) = sqrt(1900)
vf = 43.59 m/s