a car starts from rest. when it is at a distance s from its starting point its speed

markosheehan

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May 12, 2016
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a car starts from rest. when it is at a distance s from its starting point its speed is v and its acceleration is 25v+v³. show that dv=(25+v²)ds and find (correct to 2 decimal places) its speed when s=.01
this is how i went about it
dv/dt= acceleration dv/dt=dv/ds
×ds/dt=v×dv/ds

v dv/ds=25v+

dv/ds+25+

dv=(25+
v²)ds i can get this but i do not understand how to get speed when s=.01
 
a car starts from rest. when it is at a distance s from its starting point its speed is v and its acceleration is 25v+v³. show that dv=(25+v²)ds and find (correct to 2 decimal places) its speed when s=.01
this is how i went about it
dv/dt= acceleration dv/dt=dv/ds
×ds/dt=v×dv/ds

v dv/ds=25v+

dv/ds
= 25+
dv=(25+
v²)ds i can get this but i do not understand how to get speed when s=.01

dv/(25+v2) = ds

dv/(52 + v2) = ds

The LHS looks like integration of a standard form [tan-1(x)]
 
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