Answer:
(-7.5, 3.5)
Step-by-step explanation:
Answer:
44 mph
Step-by-step explanation:
Given that:
Before lunch :
Time taken = 2hrs ; at speed = x mph
After lunch :
Time taken = 3hrs ; at speed = x + 10 mph
Total distance covered = 250 miles :
Distance = speed * time
(2 * x) + (3 * (x + 10)) = 250
2x + 3x + 30 = 250
5x + 30 = 250
5x = 250 - 30
5x = 220
x = 220/ 5
x = 44 mph
Rate before lunch is 44mph
The technique of matrix isolation involves condensing the substance to be studied with a large excess of inert gas (usually argon or nitrogen) at low temperature to form a rigid solid (the matrix). The early development of matrix isolation spectroscopy was directed primarily to the study of unstable molecules and free radicals. The ability to stabilise reactive species by trapping them in a rigid cage, thus inhibiting intermolecular interaction, is an important feature of matrix isolation. The low temperatures (typically 4-20K) also prevent the occurrence of any process with an activation energy of more than a few kJ mol-1. Apart from the stabilisation of reactive species, matrix isolation affords a number of advantages over more conventional spectroscopic techniques. The isolation of monomelic solute molecules in an inert environment reduces intermolecular interactions, resulting in a sharpening of the solute absorption compared with other condensed phases. The effect is, of course, particularly dramatic for substances that engage in hydrogen bonding. Although the technique was developed to inhibit intermolecular interactions, it has also proved of great value in studying these interactions in molecular complexes formed in matrices at higher concentrations than those required for true isolation.
If Susan had 2$ and got to 12$ we need to find what multiplied by 2 = 12. So, 12/2=6
If 6x2=12 then 11x6=66
66$
