'Suppose your hand moves upward by 0.50m while you are throwing the ball. The ball leaves your hand with an upward velocity of 2
0.0 m/s. Find the magnitude of the force (assumed constant) that your hand exerts on the ball. Ignore air resistance.' Now my question is not 'What is the magnitude' but rather: why did I get (roughly) the same answer using F=ma when you were supposed to use the total mechanical energy (W+K1+U1=K2+U2). So I'm more confused about how the 2 formulas are 'related', what the force actually represents in both, when to use what and if there is an actual difference.
1 answer:
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Answer:
v = 7934.2 m/s
Explanation:
Here the total energy of the Asteroid and the Earth system will remains conserved
So we will have
now we know that
now from above formula
now we have
now plug in all data
<h2>20. How much charge is on sphere B after A and B touch and are separated?</h2><h3>Answer:</h3>
We'll solve this problem by using the concept of electric potential or simply called potential , which is <em>the energy per unit charge, </em>so the potential
at any point in an electric field with a test charge
at that point is:
The potential due to a single point charge q is:
Where is an electric constant,
is value of point charge and
is the distance from point charge to where potential is measured. Since, the three spheres A, B and C are identical, they have the same radius
. Before the sphere A and B touches we have:
When they touches each other the potential is the same, so:
From the principle of conservation of charge <em>the algebraic sum of all the electric charges in any closed system is constant. </em>So:
Therefore:
So after A and B touch and are separated the charge on sphere B is:
First: A and B touches and are separated, so the charges are:
Second: C is then touched to sphere A and separated from it.
Third: C is to sphere B and separated from it
So we need to calculate the charge that ends up on sphere C at the third step, so we also need to calculate step second. Therefore, from the second step:
Here and C carries no net charge or
. Also,
Applying the same concept as the previous problem when sphere touches we have:
For the principle of conservation of charge:
Finally, from the third step:
Here . Also,
When sphere touches we have:
For the principle of conservation of charge:
So the charge that ends up on sphere C is:
Before they are allowed to touch each other we have that:
Therefore, for the principle of conservation of charge <em>the algebraic sum of all the electric charges in any closed system is constant, </em>then this can be expressed as:
Lastly, the total charge on the three spheres before they are allowed to touch each other is:
Answer:
Explanation:
The magnitude of the magnetic force is
To find the angle, we make subject of the formula