Recent content by xuhq

We need to account for the headwind to calculate the drag force (as shown in my first post). However, I don't think you should account for it for the speed you use to calculate power. A stopped car will not need to do any work against the windhead to keep stopped. Power=F*V, where V should be...

A 150 lbm cartop carrier measures 51 in long by 35 in wide by 18 in high. If a 3000 lbm car is driven at 65 mph into a 10 mph headwind, the added net motor power required when the carrier is used is most nearly a. 5.9 hp b. 13 hp c. 15 hp d. 36 hp Cd=1.18...

Water flows at 5 gpm in a 1 in schedule-40 rigid steel pipe. If the initial pressure in the pipe is 20 psig, the maximum pressure that results from a rapidly closing valve is most nearly a 80 psi b 120 psi c 140 psi d 160 psi The deltaP i calculated is 122 psi, which gives 122+20=142...

Can anybody pls confirm?

It was applied twice in the sample exam, 104 and 115. I was also wondering and checked one of my books to understand the formula. Let d be the deflection, dmax the max deflection, and dst the static deflection, m*g/gc*(dmax+h)=1/2*k*dmax^2 m*g/gc=k*dst =>1/2*dmax^2-k*dst*(h+dmax)=0...