Calc help

The position (feet traveled) of a car is given by the equation s(t)=(1/4)t^2+1 find the time when the car is going the same speed as its average speed over the interval 0 to 10 seconds t=0 t=2.5 t=5 t=10 Never I think it's either t=5 or t=2.5? The end poi...

Sorry, to make it easier in my work I changed t to x. Thank you so much for your help!

Also, what could be the units for dy/dx if y is the surface area of a tumor and x is the radius of the tumor? Would it be meters per radian? (Square millimeters per millimeter Millimeters per centimeter Meters per second Gallons per hour Or meters per rad...