Answer:
Newton's second law of motion
Explanation:
Newton's second law of motion can be stated
The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
in another form,
Force = mass * acceleration
Any force of 29.4 Newtons or greater can do it.
8 miles per hour
because if it is moving at 4 miles every half hour that means you have to multiply it by two to get it in miles per hour and we all know that 4 times 2 is 8 so it would be 8 miles per hour =)