You drive a car 2.0 km to the gas station, 4.0 km to the shopping mall to let your mother off, and 4.5 km back home. The trip takes 20.0 min. What is your average speed?

3.2 m/s

4.38 m/s

8.75 m/s

0.525 m/s

Question

You drive a car 2.0 km to the gas station, 4.0 km to the shopping mall to let your mother off, and 4.5 km back home. The trip takes 20.0 min. What is your average speed?
		
3.2 m/s
		
4.38 m/s
		
8.75 m/s
		
0.525 m/s

anonymous · Answer

@Learner11

anonymous · Answer

@Nnesha

anonymous · Answer

@phi

sophiaholder · Answer

OKay so,

S = distance/time

sophiaholder · Answer

So, you would want to add up how many kilometers you traveled first.

anonymous · Answer

that would be 10.5/20.00 right?

sophiaholder · Answer

Nope. If we are trying to find miles/seconds we need to convert them

danjs · Answer

<Speed> = ....

anonymous · Answer

oh

danjs · Answer

Do you remember calculating the 'average rate of change' given two points on a graph from algebra

danjs · Answer

slope of a secant line connecting the two points on the graph...

sophiaholder · Answer

Dan can probably explain this better than me, so I leave this one to him

anonymous · Answer

I have no Idea what your talking about my brain just died

danjs · Answer

It is the same as that, except it is a graph of (Total distance traveled) vs (total time traveled)  for the y and x axis

danjs · Answer

To get the average speed - you take the initial value point (0 min, 0 km)   and the final point (20 min , (4.5+2.0+4.0) km )

and calculate the slope of the line through those

danjs · Answer

In short,    the average speed on an interval  will be the ratio of the total distance traveled over the total time traveled

anonymous · Answer

@dan815

danjs · Answer

$$ave~speed = \frac{ distance ~traveled }{ time of traveling }$$

danjs · Answer

you will get km/min   need to convert to m/s

anonymous · Answer

O.o

dan815 · Answer

http://prntscr.com/8kh2ht

dan815 · Answer

convert it into meters/second

anonymous · Answer

I DON'T UNDERSTAND x-x

danjs · Answer

$$\frac{ X~km }{ 1~\min }*\frac{ 10^3~m }{ 1~km }*\frac{ 1~\min }{ 60~s } =  \frac{ X * 10^3 }{ 60 }*\frac{ m }{ s }$$

anonymous · Answer

omg

dan815 · Answer

okay do you get that speed = d/t

anonymous · Answer

distance divided by time?

dan815 · Answer

yes speed tells you the rate of distance change over time

dan815 · Answer

you saw that 10.5 km traveled in 20 mins right

dan815 · Answer

tell me if that part is clear or not, gotta know this to move on

dan815 · Answer

10.5 = 2+4+4.5

anonymous · Answer

Everything