Force between two charges is given by
Now in order to find the acceleration of each mass
we can use
F = ma
In which one(s) of the following situations will there be an INCREASE in Kinetic Energy? Group of answer choices A block slides
1 answer:
Answer:
The Kinetic Energy INCREASE in the following situations:
a)A block slides down a frictionless incline:
e)A merry go round rotates faster due to the push by a person.
Explanation:
The energy kinetics is proportional to the square of the velocity:
We study the cases:
a)A block slides down a frictionless incline:
The gravity made a positive work and the box get a extra velocity, then the kinetics energy INCREASE
b)A box is pulled across a rough floor at constant speed:
The magnitude of the velocity does not change, so the kinetics energy does not change as well
c)A stone at the end of a string is whirled in a horizontal circle at constant speed:
The magnitude of the velocity does not change, so the kinetics energy does not change as well
d)A projectile approaches its maximum height:
If the projectile approaches its maximum height, its velocity approaches to zero. Then the kinetics Energy DECREASE
e)A merry go round rotates faster due to the push by a person.
Thanks to the push, the magnitude of the velocity INCREASE, so the kinetics energy INCREASE as well
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1) Potential difference: 1 V
2)
Explanation:
1)
When a charge moves in an electric field, its electric potential energy is entirely converted into kinetic energy; this change in electric potential energy is given by
where
q is the charge's magnitude
is the potential difference between the initial and final position
In this problem, we have:
is the magnitude of the charge
is the change in kinetic energy of the particle
Therefore, the potential difference (in magnitude) is
2)
Here we have to evaluate the direction of motion of the particle.
We have the following informations:
- The electric potential increases in the +x direction
- The particle is positively charged and moves from point a to b
Since the particle is positively charged, it means that it is moving from higher potential to lower potential (because a positive charge follows the direction of the electric field, so it moves away from the source of the field)
This means that the final position b of the charge is at lower potential than the initial position a; therefore, the potential difference must be negative: