Dimensional analysis Unit conversions Word Problems In orde

Dimensional analysis / Unit conversions Word Problems In order to save up for the down payment on his car, a student starts a part-time job at a fast-food restaurant. His job is to prepare sandwiches. There is one main requirement for keeping the job – he has to prepare at least 12 sandwiches in 30 minutes. The job pays him the minimum wage of $8.38 per hour. He works 4 days a week and gets paid once every 2 weeks. The down payment is $2500. Calculate how many sandwiches the student has to wrap in order to make the down payment. Show all your work as conversion factors and use dimensional analysis to check if your work is correct. A well-trained marathon runner trains by running 12.5 miles every day. He makes 6-minute miles and burns about 1,000 calories for every 10 miles he runs. In order to maintain a healthy weight, he makes sure to eat protein bars to make up for the calories he burns. A certain protein bar contains 20 grams of protein per bar. Protein provides 4 calories of energy per gram of protein. Calculate how many bars the runner has to consume on a day in order to provide his body with the calories burned during running. Show all your work as conversion factors and use dimensional analysis to check if your work is correct.

Solution

12 sandwiches in 30 minutes

24 sandwiches in 60 minutes

per hour wage is $ 8.38

he works 4 days a week

therefore he needs to prepare approximately 7200 sandwiches to make the down payment

2) marathon trainer runs 12.5 miles / day

burns 1000 calories for every 10 miles he run

for 12.5 miles he burns 1250 calories

protein bar contains 20 gms protein / bar

protein provides 4 calories of energy per gram of protein

1 protein bar provides 80 calories

therefore, he needs approximately 1250 / 80 = 16 protein bars in a day to provide with calories burned