Question

An object in free fall from

50 m high, so the height is

when t is h(t) = 50 – 4.9t2

.

What is the speed at

t = 2?

2. Determine the equation of the tangent line

on the curve y = x3 at the point (2.8)

Answer 1

1.

speed:

$v(t)=h'(t)=-9.8t$

$v(2)=9.8\cdot 2=19.6$ m/s

2.

$y-y_0=f'(x_0)(x-x_0)$

$f'(x)=3x^2$

$f'(2)=3\cdot 2^2=12$

$y-8=12(x-2)$

$y=12x-16$