The second law of motion states that force is equal to mass times acceleration. how much more force would be required to accelerate a fifty-ton ship at the same rate as a ten-ton ship? the same
two times
five times
ten times

Newton's second law:

F = ma

F = net force, m = mass, a = acceleration

Isolate a:

a = F/m

We can see that for an object with larger mass, we would need to apply a larger force on it to accelerate it at the same rate.

Compared to the 10 ton ship, we would need 5 times more force to accelerate a 50 ton ship at the same rate.

the velocity you are looking for is made up of two parts: horizontally velocity, vh, and its vertical velocity, vv. the actual velocity of the ball will be these two parts added together, and because velocity is a vector then they will need to be added vectorially.  

neglecting air resistance etc etc.,  

the horizontal velocity component will be constant (because there is no accelerating force in the horizontal direction.  

vh = 8 ms-1  

the vertical velocity component has an accelerating force: 'g'.  

using v = u +at where a = g = 9.81 ms-2.  

the vertical component of velocity, vv = 0 + gt = vv =9.81 x 2  

vv = 19.62 ms-1 . the zero appears because the virtical component of velocity at time t=0 is zero. remember, the ball was thrown horizontally.  

how fast it will be moving (it actual path (being a parabola )) will be the vector sum of these two.  

adding vectorally gives: -  

v = sqr root (8^2 + 19.62^2) = sqr root(64+384.9) = 21.18 or 21.2 ms-1

grav force prop 1/r squared 2r all squared is 4rsquared 1/4rsquared quartered