Answer:
The pitching speed of the ball is 19.7 m/s
Explanation:
- Here, we can use the third equation of motion,

- whereas v represents the final velocity, u represents initial velocity, a is the acceleration due to gravity and s is the displacement or distance an object traveled
- Here, the initial velocity of the the ball is given as zero and the acceleration due to gravity is 9.8 , the distance 's' is given as 20 m
- Using the equation,

- Hence, the pitching speed of the ball is 19.7 m/s
It was Niels Bohr who proposed it
Answer:
(a) 0.345 T
(b) 0.389 T
Solution:
As per the question:
Hall emf, 
Magnetic Field, B = 0.10 T
Hall emf, 
Now,
Drift velocity, 

Now, the expression for the electric field is given by:
(1)
And

Thus eqn (1) becomes
where
d = distance
(2)
(a) When 

(b) When 

2nd and only 2nd option is right