Question

1

The temperature falls from 0 degrees to -12 degrees in 32 hours. Which expression finds the change in
temperature per hour?
7 49
O24
7 49
0-25
49 7
oĀ x
49 7
O"42

Answer 1

D.
`Rate = -(49)/(4)^(\circ) /(7)/(2)\ hr`

Explanation:

Given

`T_1 =0^(\circ)`

`T_2 =-12(1)/(4)^(\circ)`

`Time = 3(1)/(2)\ hr`

Required

Determine the change in temperature per hour

This is calculated as:

`Rate = (T_2 - T_1)/(Time)`

`Rate = (-12(1)/(4)^(\circ) - 0^(\circ))/(3(1)/(2)\ hr)`

`Rate = (-12(1)/(4)^(\circ) )/(3(1)/(2)\ hr)`

Convert to improper fractions

`Rate = (-(49)/(4)^(\circ) )/((7)/(2)\ hr)`

Express as:

`Rate = -(49)/(4)^(\circ) /(7)/(2)\ hr`