# physics

1.An elastic cord is 5.0m long and 1.0cm in diameter and acts as a spring with spring constant 70 N/m, what is the young's modulus for this material?

2.A heavy uniform beam of mass 8000 kg and length 2.0m is suspended at one end by a nylon rope of diameter 2.5 cm and at the other end by a steel rope of diameter .64cm. The ropes are tied together above the beam. The unstretched lengths of the rope are 3.0 m each. What angle will the beam make with horizontal.

1. 👍 0
2. 👎 0
3. 👁 118

1. The amount of stretch is
(delta L) = F*L/(A E)
= 4 F L /( E pi D^2)

E is Young's modulaus
F is the tension force
L is the length
A is the cross ectional area

The spring constant is
k = F /(delta L)
= E pi D^2/(4L)

1. 👍 0
2. 👎 0
posted by drwls

## Similar Questions

1. ### physics

An elastic cord is 69 {\rm cm} long when a weight of 79 {\rm N} hangs from it but is 90 {\rm cm} long when a weight of 170 {\rm N} hangs from it.What is the "spring" constant k of this elastic cord?

asked by c on April 29, 2011
2. ### physics

An elastic cord is 69 cm long when a weight of 57 N hangs from it but is 87 cm long when a weight of 85 N hangs from it. What is the "spring" constant k of this elastic cord?

asked by kim on May 5, 2011
3. ### physic

Bungee Jumping. A bungee jumper jumps from a tall bridge attached to a light elastic cord (bungee cord) of unstretched length L. The cord first straightens and then extends as the jumper falls. This prevents her from hitting the

asked by Anonymous on October 20, 2013
4. ### Physics Classical Mechanics

A bungee jumper jumps (with no initial speed) from a tall bridge attached to a light elastic cord (bungee cord) of unstretched length L. The cord first straightens and then extends as the jumper falls. This prevents her from

asked by Anonymous on October 21, 2013
5. ### science

A bungee jumper jumps (with no initial speed) from a tall bridge attached to a light elastic cord (bungee cord) of unstretched length L. The cord first straightens and then extends as the jumper falls. This prevents her from

asked by mechanics on October 22, 2013
6. ### physics

An elastic cord is 65 cm long when a weight of 75 N hangs from it but is 85 cm long when a weight of 189 N hangs from it. What is the “spring” constant k of this cord

asked by leena on March 31, 2008
7. ### physics

super sam intends to jump off a 100 foot tower with an elastic cord tied to one ankle, ad the other end tied to the top of the tower. This cord is very light but very strong and stretches so that it can stop him without pulling

asked by Anonymous on March 19, 2012
8. ### physics

As part of a fundraiser, you want the new dean to bungee jump from a crane. The jump will be made from 44 m above a 2.5 m deep pool of Jello. A 30 m long bungee cord would be attached to the dean's ankle. You must convince the

asked by Brandon on March 26, 2013
9. ### Physics

A steel spring is hung vertically. Using a ruler, the lower end of the spring was measured to be 25.0cm from its upper end. However, when an object of mass 0.500kg it attracted to the lower end of the spring the spring stretches

asked by grace777 on November 22, 2016
10. ### physics

A steel spring is hung vertically. Using a ruler, the lower end of the spring was measured to be 25.0cm from its upper end. However, when an object of mass 0.500kg it attached to the lower end of the spring the spring stretches to

asked by Jack on November 18, 2016

More Similar Questions