round answer to the nearest tens

in Pre-Algebra Answers by
reshown by

Your answer

Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:
To avoid this verification in future, please log in or register.

1 Answer

The usual formula is d=v²/(2µg) where µ is the coefficient of friction of the road surface. We have to assume a value of µ, so let’s take 0.5. The formula then becomes d=v²/32 for g=32ft/s². So v²=32×175=5600 and v=74.8fps=51mph. For µ=0.4, v=66.9fps=45.6 mph, and for µ=0.6, v=82.0fps=55.9mph. When µ is small the skid is longer for the same speed. If µ=1, v=105.8fps=72.2mph, the maximum speed for maximum friction when the skid length is 175 feet. (When there is no friction,  µ=0. This is more or less icy conditions and the skid length is effectively infinite.)

The kinetic energy of the vehicle is mv²/2. This energy is dissipated through the work done by friction. The normal force on a flat surface is mg. The frictional force is µmg and the work done is the frictional force acting over the distance d, the skid length. This work is µmgd=mv²/2, and d=v²/(2µg).

by Top Rated User (599k points)

Related questions

1 answer
asked Jan 20, 2012 in Word Problem Answers by anonymous | 287 views
Welcome to, where students, teachers and math enthusiasts can ask and answer any math question. Get help and answers to any math problem including algebra, trigonometry, geometry, calculus, trigonometry, fractions, solving expression, simplifying expressions and more. Get answers to math questions. Help is always 100% free!
81,952 questions
86,346 answers
71,629 users