Sodium bicarbonate is a common base
Answer:

Explanation:
Given,
mass = 1.41 g = 0.00141 Kg
Electric field,E = 670 N/C.
We know,
Force in charge due to Electric field.
F = E q
And also we know
F = m g
Equating both the equation of motion
m g = E q

Charge of the particle is equal to 
Answer:
V / T is the slope of the graph
S = V / T so the slope of the graph will be the displacement at that point
Even tho the above assumes uniform quantities, the instantaneous displacement at any time is the slope of the graph at that point in case one has a graph that is not a straight line.
Explanation:
64-kg skater initially at rest throws a 4.0-kg medicine ball horizontally to the left. Suppose the ball is accelerated through a distance of 1.0 mm before leaving the skater's hand at a speed of 7.0 m/s. Assume the skater and the ball to be point-like and the surface to be frictionless and ignore air resistance. Use a vertical y-axis with the positive direction pointing up and a horizontal x-axis with the positive direction pointing to the right.
Required:
a. Determine the acceleration of the ball during the throw.
b. Determine the acceleration of the skater during the throw.