Answer:
The convection of heat within the mantle Rotation of liquid iron in the outer core
Explanation:
The electrical currents and convecting movements within the Earth's liquid core generate the planet's powerful magnetic field, which in turn drives the inner core in the way that can now be observed.
Answer:
The average velocity is 50 km/h south
Explanation:
The average velocity of an object is its total displacement divided by
the total time taken.
That means it is the rate at which an object changes its position from
one place to another.
Average velocity is a vector quantity.
The SI unit is meters per second.
A bicycle that starts 100 km south and is 120 km south of town after
0.4 hour.
The displacement = 120 - 100 = 20 km south
The time = 0.4 hour
The average velocity =
, where D is the displacement
and t is the time
The average velocity of the bicycle =
km/h
<em>The average velocity is 50 km/h south</em>
If you want it in meter per second, change the kilometer to meter
and change the hour to seconds
1 km = 1000 m
1 hour = 60 × 60 = 3600 seconds
The average velocity of the bicycle =
m/s south
(a) No, because the mechanical energy is not conserved
Explanation:
The work-energy theorem states that the work done by the engine on the airplane is equal to the gain in kinetic energy of the plane:
(1)
However, this theorem is only valid if there are no non-conservative forces acting on the plane. However, in this case there is air resistance acting on the plane: this means that the work-energy theorem is no longer valid, because the mechanical energy is not conserved.
Therefore, eq. (1) can be rewritten as

which means that the work done by the engine (W) is used partially to increase the kinetic energy of the airplane (
) and part is lost because of the air resistance (
).
(b) 77.8 m/s
First of all, we need to calculate the net force acting on the plane, which is equal to the difference between the thrust force and the air resistance:

Now we can calculate the acceleration of the plane, by using Newton's second law:

where m is the mass of the plane.
Finally, we can calculate the final speed of the plane by using the equation:

where
is the final velocity
is the initial velocity
is the acceleration
is the distance travelled
Solving for v, we find

Answer:
6.5e-4 m
Explanation:
We need to solve this question using law of conservation of energy
Energy at the bottom of the incline= energy at the point where the block will stop
Therefore, Energy at the bottom of the incline consists of the potential energy stored in spring and gravitational potential energy=
Energy at the point where the block will stop consists of only gravitational potential energy=
Hence from Energy at the bottom of the incline= energy at the point where the block will stop
⇒
⇒
Also 
where
is the mass of block
is acceleration due to gravity=9.8 m/s
is the difference in height between two positions
⇒
Given m=2100kg
k=22N/cm=2200N/m
x=11cm=0.11 m
∴
⇒
⇒
⇒h=0.0006467m=
Answer:
An element is a pure substance and is made of only one type of atom.
Explanation:
It cannot be broken down into a simpler substance.