Answer:
18joules
Explanation:
1/2 of 4=2
2 multiply by 9= 18 joules
Answer:
1. the electric potential energy of the electron when it is at the midpoint is - 2.9 x
J
2. the electric potential energy of the electron when it is 10.0 cm from the 3.00 nC charge is - 5.04 x
J
Explanation:
given information:
= 3 nC = 3 x
C
= 2 nC = 2 x
C
r = 50 cm = 0.5 m
the electric potential energy of the electron when it is at the midpoint
potential energy of the charge, F
F = k 
where
k = constant (8.99 x
)
electron charge,
= - 1.6 x
C
since it is measured at the midpoint,
r = 
= 0.25 m
thus,
F = 
= k
+ k
=
(
)
= (8.99 x
)( - 1.6 x
)(3 x
+2 x
)/0.25
= - 2.9 x
J
the electric potential energy of the electron when it is 10.0 cm from the 3.00 nC charge
= 10 cm = 0.1 m
= 0.5 - 0.1 = 0.4 m
F = k
+ k
=
(
+
)
= (8.99 x
)( - 1.6 x
)(3 x
/0.1+2 x
/0.4)
= - 5.04 x
J
A spring is an object that can be deformed by a force and then return to its original shape after the force is removed.
Springs come in a huge variety of different forms, but the simple metal coil spring is probably the most familiar. Springs are an essential part of almost all moderately complex mechanical devices; from ball-point pens to racing car engines.
There is nothing particularly magical about the shape of a coil spring that makes it behave like a spring. The 'springiness', or more correctly, the elasticity is a fundamental property of the wire that the spring is made from. A long straight metal wire also has the ability to ‘spring back’ following a stretching or twisting action. Winding the wire into a spring just allows us to exploit the properties of a long piece of wire in a small space. This is much more convenient for building mechanical devices.