The position of a model train, in feet along a railroad track, is given by
s(t) = 2.5t + 14
after t seconds.
(a) how fast is the train moving?
ft/sec
(b) where is the train after 4 seconds?
241 feet along the track
enter an exact number.
(c) when will the train be 29 feet along the track?
t=
sec

Part a) The speed is

Part b) After 4 seconds the trains is 24 ft along the track

Part c)

Step-by-step explanation:

we have

This is the equation of a line in slope intercept form

where

s(t) is the position of a model train in feet

t is the time in seconds

Part a) How fast is the train moving?

The speed of the train is equal to the slope of the linear equation so

The slope m is equal to

therefore

The speed is

Part b) Where is the train after 4 seconds?

For t=4 sec

substitute the value of t in the equation and solve for s

therefore

After 4 seconds the trains is 24 ft along the track

Part c) When will the train be 29 feet along the track?

For s(t)=29 ft

Substitute the value of s(t) in the equation and solve for t

subtract 14 both sides

Divide by 2.5 both sides

rewrite

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