A projectile which is fired from the ground with a velocity of 960 ft/sec, at an angle of 30° above the ground, has a height at time t of h(t)=480t–16t2. Find the time when it hits the ground again.

Question

A projectile which is fired from the ground with a velocity of 960 ft/sec, at an angle of  30° above the ground, has a height at time t of h(t)=480t–16t2. Find the time when it hits the ground again.

28.5714 · Accepted Answer

its 5

Anonymous · Answer

height has to equal 0 because its hitting the ground 0=480t-16t^2 factor 0=16t(30-t) so t=0 or 30 0 is when its fired so it must be 30 so it hits the ground again after 30 seconds