First you find the time it takes to hit the ground ...
4.9t^2 = 146.9
t^2 = 29.98 sec
t = √29.98 = 5.475
if d(t) = 4.9t^2
v(t) = 9.8t
v(5.475) = 9.8(5.475) = 53.659 m/s
Since you are in calculus, I am suprised that you did not know that the derivative of distance gives you velocity.
An object is dropped from the observation deck of the Skylon Tower in Niagara Falls, Ontario. The distance, in metres, from the deck at t seconds is given by d(t)=4.9t^2
a) the height of the observation deck is 146.9 m. How fast is the object moving when it hits the ground?
The answer is 53.655 m/s.
Could someone explain how the book got 53.655 m/s.
2 answers
It’s because this question is in unit one . We do not learn double derivatives until unit 3. So that is probably why. I had the same problem and my teacher wanted us to solve it with limits.