Exam 5 Naiiie. PHYS 191 Fall 2017 Please answer all questions with 3 significant

Question

Exam 5 Naiiie. PHYS 191 Fall 2017 Please answer all questions with 3 significant fi gures in the blanks s provided. A 55-kg skateboarder drops from rest at a On the level surface, the skater is brought to rest by a bunge and an un-stretched leng What is the skaters height of 3.5 m onto a quarter-pipe ramp on a level surtece cord with a spring constant of 1200 Nm (Seth=0 on the level su What would be the skater's speed at the bottom of the ramp? How much work does friction do on the skater? (+/- matters)_ th of 1.5m. initial potential energy? (+/-matters) gnoring friction: What would be t In actuality (with he length of bungee cord when it brings the skater to rest? th friction), the length of the bungee is 2.34 m when the skate is brought to rest m/s

Explanation / Answer

a) initial pE = mgh = 55(9.8)(3.5) =1886.5 J

b) 1886.5 = 1/2 mv^2

v= 8.28 m/s

c)1/2kx^2 = 1/2 mv^2

1200 x^2 = 55 ( 68.6)

x= 1.773 m

length of bugee= 1.773 + 1.5= 3.273 m

d)mgh = 1/2 kx^2 + work done to overcome friction

1886.5 J = 1/2 (1200)(2.34-1.5)^2 + Friction

1886.5 = 423.36 + work to overcome friction

work done to overcome friction= 1463.14J

Related Questions

Navigate

• Browse (All)
• Browse E
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.