Afootball is thrown horizontally off the top of an apartment house that is 78.4 meters high. the ball is thrownat a speed of 15 m/s. how far will the ball travel

The motion of the ball is a composition of the two motions:
- on the horizontal axis, it is a uniform motion with constant speed 
- on the vertical axis, it is a uniformly accelerated motion with initial speed  and constant acceleration  toward the ground

The laws of motion on the two directions are:


where h=78.4 m is the initial altitude of the ball. 

We want to find how far the ball travels on the x-axis. In order to do that, we must find the time t at which the ball reaches the ground, i.e. the time t at which y(t)=0:



And so now we can find the distance x(t) covered by the ball during this time:

The independent variable would be the fertilizer as it is what the dependent variable (the growth of grass) depends on.

Year  1936,  lehman predicted that the earths 'inner core' is solid. she observed that the seismic signals during her study were bent and did not pass through instead bouncing back. later it was confirmed that the earth's inner core was solid made up of nickel-iron and had a molten outer core.