Question

a marble is rolled down a ramp. The distance it travels is described by the formula d=490T^2 where d is the distance in centimeters that the marble rolls in t seconds. If the marble is released at the top of a ramp that is 3,920 cm long for what time period will the marble be more than halfway down the ramp?

Answer 1

Answer:

The period when its more than halfway

= 2 < t  ≤ 2.83 seconds   ( to nearest hundredth).

Step-by-step explanation:

When is is halfway down the ramp d = 3920/2 = 1960 cm, so:

1960 = 490 t^2

t^2 = 1960/490 = 4

t = 2 seconds.

When it reaches the bottom d = 3920 :

t^2 = 3920/490 =  8

t = 2.83 seconds.