In a particle accelerator a positron (C= +1.6 x 10-19) travels through a perpendicular magnet field with a magnitude
of 3.1 x 10-2 T. At what speed must the positron travel in order for it to experience a force of 4.75 x 10-14 N?
28. An alpha particle (2 protons and 2 neutrons) experiences a downward force of 2.9 x 10-14 N while traveling in a
magnetic field with a strength of 5.1 x 10-19 T pointing to the north. Find the speed of the particle and the direction
it must be traveling in.
29. Find the length of a wire if it experiences a .63N force when it travels through a magnetic field with a strength of
0.85T whilst carrying 5.0 amps of current.
30. A coil with 462 turns of wire, a total resistance of 36Ω , and a cross-sectional area of 0.25 m2
is positioned with its
plane perpendicular to the field of a powerful electromagnet. What average current is induced in the coil during the 0.37s
that the magnetic field drops from 3.1 T to 0.0 T?
31. A step-up transformer has a potential difference across the primary of 28 V and a potential difference across the
secondary of 3.0 × 104
V. There are 28 turns in the primary coil. How many turns are in the secondary?
32. A step-up transformer is used to create a potential difference of 1.6872 × 105
V across the secondary. The potentia
Answer:

Explanation:
The apparent brightness follows an inverse square law, therefore we can write:

where I is the apparent brightness and r is the distance from the Sun.
We can also rewrite the law as
(1)
where in this problem, we have:
apparent brightness at a distance
, where
million km
We want to estimate the apparent brightness at
, where
is ten times
, so

Re-arranging eq.(1), we find
:

Answer:
2.36 x 10^6 J
Explanation:
Tc = 0°C = 273 K
TH = 22.5°C = 295.5 K
Qc = heat used to melt the ice
mass of ice, m = 85.7 Kg
Latent heat of fusion, L = 3.34 x 10^5 J/kg
Let Energy supplied is E which is equal to the work done
Qc = m x L = 85.7 x 3.34 x 10^5 = 286.24 x 10^5 J
Use the Carnot's equation


QH = 309.8 x 10^5 J
W = QH - Qc
W = (309.8 - 286.24) x 10^5
W = 23.56 x 10^5 J
W = 2.36 x 10^6 J
Thus, the energy supplied is 2.36 x 10^6 J.
Answer:
281.25 J
Explanation:
We are told that the two objects with masses m and 3m.
Also that energy stored in the spring is 375 joules.
Now, initially the centre of mass of the system took place at rest, it means v1 = v and v2 = v/3
Thus, from principle of conservation of energy, we have;
½mv² + ½(3m)(v/3)² = 375J
(m + 3m/9)½v² = 375
(4/3)m × ½v² = 375
Multiply both sides by ¾ to get;
½mv² = 375 × ¾
½mv² = 281.25 J
Therefore, energy of lighter body is 281.25 J
Answer:
gas
Explanation:
because It is fast and easy