Answer:
Explanation:
The magnitude of the magnetic force is
To find the angle, we make 
subject of the formula
This problem is a piece o' cake, IF you know the formulas for both kinetic energy and momentum. So here they are:
Kinetic energy = (1/2) · (mass) · (speed²)
Momentum = (mass) · (speed)
So, now ... We know that
==> mass = 15 kg, and
==> kinetic energy = 30 Joules
Take those pieces of info and pluggum into the formula for kinetic energy:
Kinetic energy = (1/2) · (mass) · (speed²)
30 Joules = (1/2) · (15 kg) · (speed²)
60 Joules = (15 kg) · (speed²)
4 m²/s² = speed²
Speed = 2 m/s
THAT's all you need ! Now you can find momentum:
Momentum = (mass) · (speed)
Momentum = (15 kg) · (2 m/s)
<em>Momentum = 30 kg·m/s</em>
<em>(Notice that in this problem, although their units are different, the magnitude of the KE is equal to the magnitude of the momentum. When I saw this, I wondered whether that's always true. So I did a little more work, and I found out that it isn't ... it's a coincidence that's true for this problem and some others, but it's usually not true.)</em>
The tension in the cord is 14.7 N and the force of pull of the cord is 14.7 N, assuming the block is stationary.
<h3>
What is the tension in the cord?</h3>
The tension in the cord is calculated as follows;
T = ma + mg
where;
- a is the acceleration of the block
- g is acceleration due to gravity
- m is mass of the block
T = m(a + g)
T = 1.5(a + 9.8)
T = 1.5a + 14.7
Thus, the tension in the cord is (1.5a + 14.7) N.
If the block is at rest, the tension is 14.7 N.
<h3>Force of the force</h3>
The force with which the cord pulls is equal to the tension in the cord
F = T = m(a + g)
F = (1.5a + 14.7) N
If the block is stationary, a = 0, the tension and force of pull of the cord = 14.7 N.
Thus, the tension in the cord is 14.7 N and the force of pull of the cord is 14.7 N, assuming the block is stationary.
Learn more about tension here: brainly.com/question/187404
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