Answer:
The magnitude of the force, B = 5 Tesla, Up (North) direction
Explanation:
Magnetic force F= Eq where Electric field, E = 750 NC
and charge, q = -70 μC = -7 ×
C
F = 750 × -7 ×
F = 0.0525
But F = qvB; B = 
where B is the magnetic field
= 0.0525 ÷ ( -7 ×
× 30)
B = 5.0 Teslas
The force on a negative charge is in exactly the opposite direction to that on a positive charge.
Hence the direction of the charge is up (North).
Because of the build up of pressure. There is so much steam coming from such a compressed point, it’s coming out in force.
Now think of that same spot being closed, it only has one place to go but it can’t leave, so that pressure will build and build and then BOOM, it explodes.
In short, the answer is the pressure being released from a small point, and how that energy is released.
Via half-life equation we have:

Where the initial amount is 50 grams, half-life is 4 minutes, and time elapsed is 12 minutes. By plugging those values in we get:

There is 6.25 grams left of Ra-229 after 12 minutes.
There are 6 types of quarks.
Answer: C. 6
Answer:
Explanation:
Electric field between plates of a parallel plate capacitor is uniform .
In a uniform electric field , relation between electric field and potential gradient is as follows
electric field = potential gradient [ E = - dV / dl ]
in the given case ,
dV = 51 V ,
dl = 4 cm
= 4 x 10⁻² m
E = 51 / 4 x 10⁻²
= 12.75 x 10² V / m
= 1275 V / m