Question

1. The variables x and y vary directly. When x is 3, y is 6. Find x when y = 2/3.

2. The force acting on an object varies directly with its acceleration. A force of 25
newtons accelerates an object at 1.25 m/s. What is the acceleration of a 35
newton force?

Please help this assignment is very confusing

Answer 1

y = k x
6 = 3 k
k = 2

y = 2 x
2/3 = 2 x
x = 2/6 = 1/3
=================
25 = m (1.25)
so
m = 25/1.25

a = F/m = 35 /(25/1.25)
= 1.25 * (35/25)=1.75

You could have written that down immediately by proportions but:
1. I am a physicist
2. You are doing algebra of direct variation.