Answer:
toward the center of the circular curve
Explanation:
An object will follow a circular path at constant speed if and only if its net acceleration is constant and directed toward the center of the curved path.
__
The result force is directed toward the center of the circle.
_____
<em>Additional comment</em>
If any part of the result force is in the direction of motion, the speed will not be constant. If the center-directed force is not constant, the path will not be circular.
(a) The skater covers a distance of S=50 m in a time of t=12.1 s, so its average speed is the ratio between the distance covered and the time taken:

(b) The initial speed of the skater is

while the final speed is

and the time taken to accelerate to this velocity is t=2 s, so the acceleration of the skater is given by

(c) The initial speed of the skater is

while the final speed is

since she comes to a stop. The distance covered is S=8 m, so we can use the following relationship to find the acceleration of the skater:

from which we find

where the negative sign means it is a deceleration.
It appears to be a <span>spiral shape. </span>
Answer:
Mass of the oil drop, 
Explanation:
Potential difference between the plates, V = 400 V
Separation between plates, d = 1.3 cm = 0.013 m
If the charge carried by the oil drop is that of six electrons, we need to find the mass of the oil drop. It can be calculated by equation electric force and the gravitational force as :


, e is the charge on electron
E is the electric field, 


So, the mass of the oil drop is
. Hence, this is the required solution.