homework help needed

Question

An object is thrown upward at a speed of 168 feet per second by a machine from a height of 8 feet off the ground. The height  of the object after tt seconds can be found using the equation h(t)=−16t2+168t+8h(t)=-16t2+168t+8. Give all numerical answers to 2 decimal places.

When will the height be 28 feet? At  units: 

When will the object reach the ground?   units: 

When will the object reach its maximum height?   units: 

What is its maximum height?   units: 

Answer 1

where I have t equals make sure you include seconds after the values and for h(t) equals include feet after the value. Hope this helps and if you have any questions feel free to let me know.