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the speed of a brick traveling on a horizontal frictional surface changes iPad 7

ID: 1780375 • Letter: T

Question

the speed of a brick traveling on a horizontal frictional surface changes iPad 7:52 AM 51% usq45tx.theexperta.com ¢+ Enrollment: Add to Cart The Expert TA I Human-like Grading, Automated! Home Student: 15294548uhw.edu My Account Log Out Homework 11 Begin Date: 118/2017 4.00.00 PM Due Date: 11/13/2017 11:59:00 PM Ead Date: 11/15/2017 11:59.00 PM (9%) Problem 4: You have a spring with a spring constant 4800 Nm. Randomized Variables -4800 N/m. 50% Part (a) If you want to store 165 J of energy in this spring, should you compress it or stretch it? Either can be done. O You must compress it rade Summars OYou must stretch itEnergy cannot be stored in a spering Dedactions Posential Submissioas Allenets remain aive Hints: deduction per hint. lints remaning: Feedback: doduction per foodhack 11 por atemp 50% Part (b) How far, in centimeters, would you have to compress this spring to store this energy?

Explanation / Answer

Part (A) Both way (Compressing or stretching), energy can be stored in the spring. The stored energy, E in spring is given by:

E = kx2/2 Where k = Spring constant & x = displacement (x is +ve for expansion and -ve for compression).

Thus Answer: Either can be done. (Part A)

Part (B) Energy stored, E = 165 J

thus, kx2/2 = 165

4800*(x2)/2 =165

Thus x = 0.262 m = 26.2 cm (Answer Part B)