Question:
Mateo drew the field lines around the ends of two bar magnets but forgot to label the direction of the lines with arrows. In which direction should an arrow at position 1 point?
left
right
up
down
Answer:
The correct answer is
Left
Explanation:
Magnetic circuits describe the path of a magnetic flux. In the same way electricity follows a complete closed circuit, the path of a magnetic flux is also a complete and closed circuit which leaves from the N pole, migrates through the air and reenters the magnet through the S pole through which it passes back into the magnet to come to the N pole again.
As such the magnetic field lines emanate from the N pole which is on he right to the S pole which is on the left. Hence the arrow should point in the left direction.
Answer: 
Explanation:
Density is a characteristic property bodies and materials, and is defined as the relationship between the mass 
and the volume 
, as shown below:
(1)
In the case of the neutron star, we know it has the same mass as the Sun:
And its radius is 
On the other hand, if we assume this neutron star has a spherical shape, its volume can be calculated by the following formula:
(2)
(3)
(4)
Substituting (4) in (1):
(5)
Finally:
Answer:
Buildings absorb heat during the day and radiate heat at night. So, temperatures at night become warmer than normal. This warmth prevents fog formation because fog formation requires low temperatures.
Explanation:
Answer:
180 kJ
Explanation:
Given that:
Mass (m) = 5 kg
Initial temperature (T1) = 28°C
Final temperature (T2) = 68°C
The change in temperature (ΔT) = T2 - T1 = 68°C - 28°C = 40°C
Specific heat capacity of aluminium (c) = 900 J/kg°C
The quantity of heat energy required (q) is given by:
q = mcΔT
q = 5 kg × 900 J/kg°C × 40°C
q = 180000 Joules
q = 180 kJ
Therefore 180 kJ is required to raise the temperature of aluminium from 28°C to 68°C.
