Answer: a) 127 eV; b) there is no change of kinetic energy.
Explanation: In order to explain this problem we have to use the change of potentail energy ( conservative field) is equal to changes in kinetic energy. So for the proton ther move to lower potential then they gain kinetic energy from the electric field. This means the electric force do work in this trayectory and then the protons increased changes its speed.
If we replace the proton by a electron we have a very different situaction, the electrons are located in a lower potental then they can not move to higher potential if any external force does work on the system.
In resumem, the electrons do not move from a point with V=87 to other point with V=-40 V. The electric force point to high potential so the electrons can not move to lower potential region (V=-40V).
Answer:
induced EMF = 240 V
and by the lenz's law direction of induced EMF is opposite to the applied EMF
Explanation:
given data
inductance = 8 mH
resistance = 5 Ω
current = 4.0 A
time t = 0
current grow = 4.0 A to 10.0 A
to find out
value and the direction of the induced EMF
solution
we get here induced EMF of induction is express as
E = - L
...................1
so E = - L 
put here value we get
E = - 8 ×

E = -40 × 6
E = -240
take magnitude
induced EMF = 240 V
and by the lenz's law we get direction of induced EMF is opposite to the applied EMF
Answer:
Scalar quantity can never be Negative. Because scalar has only magnitude not direction. And magnitude can't be negative.
Explanation:
Answer:
<h2>34.67 W</h2>
Explanation:
Power is the rate at which work is done and can be found by using the formula

p is the power in Watts (W)
w is the workdone in joules
t is time in s
but workdone = force × distance
From the question
force = 780 N
distance = 2 m
workdone = 780 × 2 = 1560 N
Since we now have the value of workdone we can find the power
We have

We have the final answer as
<h3>34.67 W</h3>
Hope this helps you