# What is the answer? question 3

Today’s What is the answer blog has a dynamics question.  Here we go…

You are driving a car at 90 km/hr on a dry road and suddenly brake to stop.  If the coefficient of friction between the tires and the road is 0.63 what is the minimum stopping distance?

A. 34 m

B. 40 m

C. 51 m

D. 73 m

# What is the answer? question 2

Today’s What is the answer question comes from mechanics of materials.   Here we go…

A 1/2 inch diameter steel rod is stretched between two fixed points.  At a temperature of 72 degrees Fahrenheit the tensile load in the rod is 850 pounds.  At approximately what temperature (in degrees Fahrenheit) will the stress in the rod be zero?

A.  85

B.  95

C.  105

D.  115

# What is the answer? question 1

What is the answer?  Thermodynamics question 1

Today’s question is a quick thermodynamics question.  Here we go…

A refrigerator has a coefficient of performance of 6.0 and the room temperature outside the refrigerator is 28 degrees Celsius.  The lowest temperature (in Celsius) that can be obtained inside the refrigerator is:

A.  5

B.  -10

C.  -15

D.  12

Work the problem and see if you can find the correct answer.  Give a comment below with the answer once you are done.  Also, share this with other so that more people get the practice.  Once you have done all of that… head on over to the Mechanical PE Academy Facebook page, where you will get updates and exclusive content.

# Introduction to the ‘What is the answer?’ blog series

For every pass I caught in a game, I caught a thousand in practice.”  ~ Don Hutson

Welcome to a new blog series… What is the answer?

Let me see if I can summarize the typical engineer wanting to take the PE exam.  You graduated from college and quickly started your first real engineering job.  Almost immediately you forget most of what you worked so hard to learn during college.  Your new job doesn’t require you to use most of your education, so you gradually forget even more.  You work for 4 years or so… and now you want to take the PE exam.  You grab a few books to start reviewing for the exam, and it is at that moment you realize that you don’t remember any of this!  Simple statics problems seem unbelievably difficult!  The only thing you remember about thermodynamics is that there is no such thing as cold… only absence of heat!  How are you going to relearn all of this material for the exam?

If that sounds anything like you… you are not alone!  Relearning all of that material must be a gradual process.  One must work a lot of problems to practice the material again.  How do you find the time to work a lot of problems?  That is where this blog series can help!

So what is this blog about?