Answer
The ball's height 3 seconds after it was kicked was 40 feet.
Work Step by Step
A football was kicked vertically upward from a height of 4 feet with an initial speed of 60 feet per second. The formula $$h=4+60t−16t^{2}$$
describes the ball's height above the ground, h, in feet, t seconds after it was kicked.
What was the ball's height 3 seconds after it was kicked?
2 seconds represents the time, t, so substitute the 3 for each t in the equation:$$h=4+60(3)−16(3)^2$$
Work exponents first:$$h=4+60(3)−16(9)$$
Figure all division and multiplication next (in order left to right):$$h=4+180−144$$
Then complete all addition and subtraction in order left to right:$$h=184−144$$ $$h=40$$
