Answer:
160,000 N
Explanation:
Given:
m = 320,000 kg
v₀ = 0 m/s
a = constant
t = 57 s
Δx = 810 m
Find: Fnet
Apply Newton's second law:
∑F = ma
Fnet = ma
To find Fnet, we must first find the acceleration.
x = x₀ + v₀ t + ½ at²
810 m = 0 m + (0 m/s) (57 s) + ½ a (57 s)²
a = 0.50 m/s²
Fnet = (320,000 kg) (0.50 m/s²)
Fnet = 160,000 N
To solve this problem we will apply the concepts related to the conservation of momentum. The momentum can be defined as the product between the mass of the object and its velocity, and the conservation of the momentum as the equality between the change of the initial momentum versus the final momentum. Mathematically, this relationship can be described as
Here,
= Mass of each object
= Initial velocity of each object
= Final velocity of each object
According to the statement one of the bodies does not have initial velocity, therefore said term would be zero. And the equation could be rewritten as,
Replacing the values respectively (The mass of your body with its respective speed we would have)
Therefore the initial velocity of the 2kg cart is 0.55m/s
Apparently, the question is looking for A. electric potential energy;
but I don't think that's quite right. Electric potential difference is expressed in Joules / Coulomb which is the work to move a charge between 2 points
Example: If the electric field between, say, between 2 capacitor plates is
E = 100 Newtons / Coulomb then the work done in moving a unit of charge from the negative plate to the positive plate separted by 1 cm is
V = E * d = 100 Newtons / Coulomb * .01 meters = 1 Newton-meter / Coulomb
= 1 Joule / Coulomb which is the electric potential or potential difference
(The definition of electric potential between points is "the work moving a unit positive test charge from one point to the other")
Now in our above example where V = 1 Joule / Coulomb
if we move 10 Coulombs from the negative plate to the positive plate
W = V Q = 1 Joule / Coulomb * 10 Coulombs = 10 Joules
where work done has the correct units of Joules.
Your textbook should help clarify this.
The stroke that begins a point in volleyball is called a serve