can someone explain to me how to solve the problem

Question

the weight W that a horizontal beam m. Suppose an 8 meter beam can support 1200kg. How many kilograms can a 14 meter beam support? round to the nearest kilogram

Answer 1

This is a basic ration problem with several ways to set it up:

 

1)  You can set up the proportions as meters/kg

     In English:  8m is to 1200kg as 14m is to xkg... It looks like this:   

     8/1200 = 14/x

     Cross multiply and solve for x

     8x = 14(1200)

     x = 14(1200)/8

     x = 2100kg

 

2) You can also check the change in the initial variable

    and multiply the other by the same amount...

    (8m)(x) = 14m

    x = 14/8 = 1.75

    Since we multiplied the length by 1.75 we multiply the weight

    limit by the same amount:

   (1200kg)(1.75) = 2100 kg