HI ,

Could you please help me to check my answer for the below question? Thanks

A projectile is launch with an initial speed of 140feet per second from a 20 feet tall tower at an angle of pi/3 to the horizontal. Assume that the only force acting on the object is gravity.

Find the maximum horizontal range.

Solution:

x=70t

y=70sqrt(3)t -16t^2

The projectile will reaches its maximum horizontal range when it hit the ground that is when y=0.

y=70sqrt(3)t -16t^2=0

so t=0 (ignored) or t= 35sqrt(3)/8

x=70t =70 x 35sqrt(3)/8 = 530.44 ft

So the maximum horizontal range is 530.44ft.

Is my answer correct? The reason I asked that because my friend got a different answer. Her answer is 541.8feet.