In this question we will convert the top and the bottom units but there's no need to worry I'll walk you right through it so you can get it right on your next exam. Hello everyone I'm Melissa Maribel your personal tutor and this question asks us to convert 55 miles per hour to nanometers per second since there are a bit more units to convert for this question we will break this question up into two steps step one will be converting the top units to nanometers and step two will be converting the bottom units to seconds let's convert miles to nanometers by choosing what conversion factors we'll need the first conversion factor must have the same unit as our given unit which is miles so this is our first conversion factor and that allows us to get to meters so now the second conversion factor must have meters in it we will use the metric system to help us go from meters to nanometers here's our proper setup start with the given unit of fifty five miles on top and hours on the bottom and there's really just a one on the bottom with the hours. Align the given units of miles across so they can cancel and on top we'll put meters that was our first conversion factor next align the same unit of meters across and those will cancel to get our different unit of nanometers this was our second conversion factor now multiply straight across and divide we will get this value with nanometers divided by hours as our units so step two is to convert the hours on the bottom to seconds let's pick our conversion factors the first conversion factor will have hours in it and that will allow us to get two minutes the second conversion factor will now have minutes in it and that allows us to get two seconds now this is a tiny bit different we won't align the units this way but instead we will align them this way so the bottom unit of hours can cancel we will use our first conversion factor and align the hours so they can cancel so now at minutes using the second conversion factor align the minutes across from each other so they can cancel and we're left with seconds on the bottom and nanometers on top which is what we wanted initially now divide the 8.9 by the bottom numbers multiplied and we'll get this value but make sure to round to two sig figs since 8.9 only has two sig figs and this is the correct value. You wanna know a secret to acing your next exam it's practice! There are plenty of examples right over here to help you out with that and remember stay determined you can do this!