Answer:
Vp = 1 [m/s]
Explanation:
In order to solve this problem, we must use the principle of conservation of the amount of movement. In the same way, analyze the before and after of the actions.
<u>The moment before</u>
The 50kg person is still hold (no movement) with the 2kg helmet
<u>The moment after</u>
The helmet moves at 25[m/s] in one direction, the person moves in the opposite direction, due to the launch of the helmet.
In this way we can apply the principle of conservation of movement, expressing the before and after. To the left we have the before and to the right of the equal sign we have the after.
Σm*V1 = Σm*V
where:
m = total mass = (2 + 50) = 52[kg]
V1 = velocity before the lunch = 0
(50 + 2)*V1 = (25*2) - (Vp*50)
0 = 50 - 50*Vp
50 = 50*Vp
Vp = 1 [m/s]
Work = (force) x (distance)
You could look at the two cases, and see right away that
the first one has more force acting through more distance,
so it must be more work. But since I just gave you the formula
for Work, let's calculate the amount of it for both cases:
First case: Work = (115 N) x (15 m) = 1,725 joules
Second case: Work = (20 N) x (10 m) = 200 joules
The first case involves 8.625 times as much work as the second case.
Answer:
There is at least one instant which instantaneous acceleration is equal to average acceleration. 
.
Explanation:
The average acceleration experimented by the car is:
According to the Rolle's Theorem, there is at least one instant t so that instantaneous acceleration equal to average acceleration for the analyzed interval. That is to say:
If car is accelerating at constant rate, instantaneous acceleration coincides with average acceleration for all instant t. Then, instantaneous acceleration is:
Answer:
W = 2.74 J
Explanation:
The work done by the charge on the origin to the moving charge is equal to the difference in the potential energy of the charges.
This is the electrostatic equivalent of the work-energy theorem.
where the potential energy is defined as follows
Let's first calculate the distance 'r' for both positions.
Now, we can calculate the potential energies for both positions.
Finally, the total work done on the moving particle can be calculated.
Answer:
D
Explanation:
When the spring is wound, then it gathers potential energy in the form of tension energy. As it slowly unwinds, the potential energy is converted to kinetic energy of the hands' movements of the clock. This energy is channeled through the use of cogs/gears in the clock.
