Answer:
30.29 s
Explanation:
We are given that
Radius=r=6 cm
Length of an arc=l=19 cm
We have to find the value of t in seconds.

Substitute the values then we get

We know that
1 minute=60 seconds
In 60 seconds ,second hand makes an angle=
radian
radian made by second had in 60 sec.
1 radian made by second hand in
sec
3.17 rad made by second hand in 
Hence, the value of t =30.29 s
Answer:
m = B²qR² / 2 V
Explanation:
If v be the velocity after acceleration under potential difference of V
kinetic energy = loss of electric potential energy
1/2 m v² = Vq ,
v² = 2 Vq / m ----------------------- ( 1 )
In magnetic field , charged particle comes in circular motion in which magnetic force provides centripetal force
magnetic force = centripetal force
Bqv = mv² / R
v = BqR / m
v² = B²q²R² / m² ------------------------- (2)
from (1) and (2)
B²q²R² / m² = 2 Vq / m
m = B²q²R² / 2 Vq
m = B²qR² / 2 V
Es la radiacion terrestre emitida por la Tierra como consecuencia de su temperatura.