Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

1. A force of 5.0 N is required to stretch a certain spring by 1.5 c m . a) How

ID: 2144076 • Letter: 1

Question

1. A force of 5.0N is required to stretch a certain spring by 1.5cm .

a) How far must this spring be stretched for its potential energy to be 0.025J ?

b)How much stretch is required for the spring potential energy to be 0.080J ?


2. A 18000 kg airplane lands with a speed of 72 m/s on a stationary aircraft carrier deck that is 115 m

long.

a.) Find the work done by nonconservative forces in stopping the plane.


3.) A particle moves under the influence of a conservative force. At point

A the particle has a kinetic energy of 10J ; at point Bthe particle is momentarily at rest, and the potential energy of the system is 27J ; at point C the potential energy of the system is 5J .

a.) What is the potential energy of the system when the particle is at point A ?

b.) What is the kinetic energy of the particle at point C ?



J

Explanation / Answer




F=k*x...

spring constnt k=F/x=5/0.015=333.34 N/m...

A)P.E=U=(1/2)*k*x^2...

x=sqrt[2*u/k]=0.01224 m=1.224 cm

B)x=sqrt[2*u/k]=0.0219m=2.19 cm

C)W=

F=m*a=m(u^2/2s)=4.057*10^5 N

W=F.S=4.67*10^7 J


3)
a)total energy TE=K.E+P.E...

at B T.E=0+P.E=27 J...

at A P.E=T.E-K.E=27-10=17J

B)at C K.E=T.E-P.E=27-5=22 J