Answer:
28.2 m/s
Explanation:
The range of a projectile launched from the ground is given by:

where
v is the initial speed
g = 9.8 m/s^2 is the acceleration of gravity
is the angle at which the projectile is thrown
In this problem we have
d = 81.1 m is the range
is the angle
Solving for v, we find the speed of the projectile:

The Kinetic energy of an object is given by:

Where m is the mass of the object (kg) and v is the velocity of the object (ms-1)
Substituting in:

Therefore the Kinetic energy of the object is
1.35MJ
Answer:
charge = electrons + protons
=92+92
=184
Since 1m/s goes to 4m/s in 3 seconds,
then 4m/s goes to 8m/s in 6 seconds.
So your answer would be:
4m/s to 8m/s in 6 seconds