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A 2430 pound roller coaster starts from rest and is launched such that it crests a 105 ft high hill with a speed of 59 mph. The roller coaster travels 396 ft in reaching the top of the hill and there is a constant drag force of 85 pounds. Determine launch energy

Respuesta :

Answer:

Explanation:

Given

Weight of roller coaster is [tex]W=2430\ pound[/tex]

mass of roller coaster [tex]m=\frac{W}{g}=\frac{2430}{32.2}=75.45 [/tex]

Distance traveled by roller coaster [tex]d=396\ ft[/tex]

drag force [tex]f_d=85\ pounds [/tex]

velocity at top [tex]v=59 mph\approx 86.53\ ft/s[/tex]

Suppose E is the initial energy

Conserving Energy at bottom and top

[tex]E=\frac{1}{2}mv^2+mgh+f_d\cdot d[/tex]

[tex]E=0.5\times 75.45\times 86.53^2+2430\times 105+85\times 396[/tex]

[tex]E=2.9\times 10^5\ foot-pound[/tex]