Answer: 
Explanation:
The acceleration of the motorcycle is given by

where
v=24 m/s is the final velocity of the motorcycle
u=15 m/s is the initial velocity
t=3 s is the time taken
Substituting these numbers into the equation, we find

Answer:
The answer is the 3rd option!
An electron is emitted in both positive and negative beta decay, although the positive one is called positron emission.