Newton's second law of motion involves the effect of force acting on a mass.
It has to be understood that this actually means the combination of any and
all individual forces acting on it, with their individual strengths and directions
all added together.
When all the individual forces acting on an object add up to zero, then the
whole group of forces is said to be 'balanced'.
When all the individual forces acting on an object don't add up to zero, then
the whole group of forces is said to be 'unbalanced'.
Notice that there's no such thing as 'a balanced force' or 'an unbalanced force'.
It's a <u>group</u> of two or more forces that's balanced or unbalanced.
Answer:
Explanation:
Let's use Ohm's law:
or
(1)
Where:
We know the value of the voltage V, so we need to find the value of R in order to find I. Fortunately there is a relation between the resistivity of a conductor and its electrical resistance given by:
(2)
Where:
Keep in mind that the electrical resistivity of the gold is a known constant which is 
and the cross sectional area of the conductor is calculated as:
Because we have a wire in this case, so we assume a cylindrical geometry.
Now replacing our data in (2)
Finally, we know R and V, so replacing these values in (1) we will be able to find the current:
In order to compute the final velocity of the trains, we may apply the principle of conservation of momentum which is:
initial momentum = final momentum
m₁v₁ = m₂v₂
The final mass of the trains will be:
10,000 + 10,000 = 20,000 kg
Substituting the values into the equation:
10,000 * 3 = 20,000 * v
v = 1.5 m/s
The final velocity of the trains will be 1.5 m/s
Answer:
the force of the plow pulling backward on the tractor
Explanation:
