Answer:
The magnetic field at a distance of 19.8 cm from the wire is 1.591 mT
Explanation:
Given;
first magnetic field at first distance, B₁ = 2.50 mT
first distance, r₁ = 12.6 cm = 0.126 m
Second magnetic field at Second distance, B₂ = ?
Second distance, r₂ = ?
Magnetic field for a straight wire is given as;

Where:
μ is permeability
B is magnetic field
I is current flowing in the wire
r distance to the wire

Therefore, the magnetic field at a distance of 19.8 cm from the wire is 1.591 mT
Answer:
True The net force must be zero for the acceleration to be zero
Explanation:
In order to analyze the statements of this problem we propose your solution.
First let's look at Newton's first, which stable that every object is at rest or with constant speed unless something takes it out of this state (acceleration)
Now let's look at the second postulate, which says that force is related to the product of the mass of a body and its acceleration.
As a result of these two laws, for a body is a constant velocity the summation force on it must be zero.
Now we can analyze the statements given.
True The net force must be zero for the acceleration to be zero
False. If the force is different from zero, there is acceleration that changes the speeds
False. There may be forces, but the sum of them must be zero
False. If a force acts, the acceleration is different from zero and the speed changes
If the net force is 4 N, and Frankie is pulling the rope with 7 N, Carol must be pulling the rope with 11 N (I think that Carol is going to win the tug-of-war...).
Answer: v = 0.6 m/s
Explanation: <u>Momentum</u> <u>Conservation</u> <u>Principle</u> states that for a collision between two objects in an isolated system, the total momentum of the objects before the collision is equal to the total momentum of the objects after the collision.
Momentum is calculated as Q = m.v
For the piñata problem:


Before the collision, the piñata is not moving, so
.
After the collision, the stick stops, so
.
Rearraging, we have:


Substituting:

0.6
Immediately after being cracked by the stick, the piñata has a swing speed of 0.6 m/s.
The 'phases' are solid, liquid, gas. A change from any one of those to any other one is a phase change. Like melting ice, or evaporating sweat.