C . Record the time to complete a chemical reaction
The answer is C hope this helps <span />
Answer:
Speed of the alpha particle is
Explanation:
We have given charge on alpha particle 
Mass of the alpha particle 
Potential difference 
We have to find the speed of the alpha particle
From energy conservation we know that



Answer:
115, 80, 15m
Explanation
t1 = 14s
t2 = 18s
change in time = 4s (18-14)
r(final) = r(initial) + (average velocity) x (change in time)
multiply the average velocity with the change in time
= (4, 0, -3) x 4 = 16, 0, -12
now we'll add this value to the initial position of the car
(99, 80, 27)m + (16, 0, -12)m = (115, 80, 15)m