Math Is Fun Forum

missbossyy

Member

Registered: 2008-02-01

Posts: 38

Story type problem in diff. equations

Under some circumstances a falling body B of mass m, such as the skydiver, encounters air resistance proportional to its instantaneous velocity v. Use Newton's second law to find the differential equation for the velocity v of the body at time t. Recall that acceleration is a = dv/dt. Assume in this case that the positive direction is downward.

EXPLAIN THE WAY THAT IT WILL BE HELPFUL FOR MY PREPARATION OF THE TEST....

JaneFairfax

Member

Registered: 2007-02-23

Posts: 6,868

Re: Story type problem in diff. equations

The freefalling skydiver experiences two forces: his weight mg, and the air resistance −kv, where k > 0 is the constant of proportionality. Hence, by Newton’s second law,

missbossyy

Member

Registered: 2008-02-01

Posts: 38

Re: Story type problem in diff. equations

thanks!