How to find the distance-Physics ?

Question

You leave your mom's house and go 80 km/h for 100 km. Then it starts to snow and you slow down to 50 km/hr. You arrive home after driving 2.0 hours. How far is your mom's house from your home?

Can someone please tell me how to complete this problem. I need a detailed answer. Thanks in advance. I'm working a problem similar to this, I just need to figure out how to do this problem.

Answer 1

137.5 km

u drove for 1.25 hrs to cover 100km in a speed of 80kmph (100km/80kmph = 1.25h)

u reached ur Mom's house after driving for 2 hrs. so u drove for .75 hrs in a speed of 50kmph which makes u to cover a distance of 37.5 km (.75h*50kmph = 37.5km)

so totally u have covered 137.5km (100km+37.5km)

Answer 2

First take the distance of 100km and divide by the speed 80 km/hr.  This will tell you how long you have been traveling 1.25 hours.  Your total journey is 2 hours, so you have .75 hours remaining.  Multiply 50 km/hr x .75 hrs = 37.5 km.  So the total distance is 137.5 km.

Answer 3

If you travel at 80 km/hour for 100 km, you will spend 1.25 hours driving that distance.

The remaining 3/4 of an hour is spent driving at 50 km/hour. At that rate of speed and for that amount of time, you will have traveled 37.5 km for the rest of the trip.

Adding the two distances means that the total distance is 137.5 km.

Answer 4

d=(80km/h)(2 hours)+(-50km/h)(4)

                               -----------------

                                      2

d=160km+-200km

                ----------

                   2

d=160km+-100km

d=60km

or

f you travel at 80 km/hour for 100 km, you will spend 1.25 hours driving that distance.

The remaining 3/4 of an hour is spent driving at 50 km/hour. At that rate of speed and for that amount of time, you will have traveled 37.5 km for the rest of the trip.

Adding the two distances means that the total distance is 137.5 km.