Answer:
1) Q ’= 8 Q
, 2) q ’= 16 q
, 3) r ’= ¾ r
Explanation:
For this exercise we will use Coulomb's law
F = k q Q / r²
It asks us to calculate the change of any of the parameters so that the force is always F
Original values
q, Q, r
Scenario 1
q ’= 2q
r ’= 4r
F = k q ’Q’ / r’²
we substitute
F = k 2q Q ’/ (4r)²
F = k 2q Q '/ 16r²
we substitute the value of F
k q Q / r² = k q Q '/ 8r²
Q ’= 8 Q
Scenario 2
Q ’= Q
r ’= 4r
we substitute
F = k q ’Q / 16r²
k q Q / r² = k q’ Q / 16 r²
q ’= 16 q
Scenario 3
q ’= 3/2 q
Q ’= ⅜ Q
we substitute
k q Q r² = k (3/2 q) (⅜ Q) / r’²
r’² = 9/16 r²
r ’= ¾ r
Both valves are closed during the power stroke.
While the fuel is burning in the cylinder, you want
all the force of the expanding gases to push the
piston down ... you don't want any of the gases
or their pressure escaping.
If either of the valves was open, even just a crack,
then part of the gases would go blooey out the valve,
and some pressure would be lost that's supposed to be
pushing the piston.
made from pure metals . . . no;
they've been made from all kinds of weird compounds and alloys.
conduct electricity with zero resistance . . . yes;
that's why they're called "superconductors".
produce a strong magnetic field . . . possible, but not because it's a superconductor;
just like any other conductor, the magnetic field depends on the current that's flowing in the conductor.
no loss of energy in the transfer of electricity . . .
there's no loss of energy in the current flowing in the superconductor;
but if you tried to transfer the current out of the superconductor into
something else, then there would be some loss.
Answer:
90,000 J
Explanation:
Kinetic energy can be found using the following formula.
where <em>m </em>is the mass in kilograms and <em>v</em> is the velocity in m/s.
We know the object has a mass of 50 kilograms. We also know it is a traveling at a rate of 60 m/s. Velocity is the speed of something, so the velocity of the object is 60 m/s.
<em>m</em>=50
<em>v</em>=60
Substitute these values into the formula.
First, evaluate the exponent: 60^2. 60^2 is the same as multiplying 60, 2 times.
60^2=60*60=3,600
Multiply 50 and 3,600
Multiply 1/2 and 3,600, or divide 3,600 by 2.
Add appropriate units. Kinetic energy uses Joules, or J.
The kinetic energy of the object is 90,000 Joules
