Help with Hookes Law Question

jmckee603

2

Help with question 6 parts A and B. Thanks!

Reply 1

sherv1360

1

energy of a spring = 1/2 kx^2 we have x which is compression/extension and k=2.4 work out energy which equals 0.27 (convert cm into m and the kN/M into N/M) you get e=0.27 joules. the change in height is = 0.6 -0.1=0.5 You know that E=MGH soe equate the 2 equations giving you
MGH = 0.27 so m=0.27/(9.81X0.5)

Reply 2

NoahMal

17

Original post by jmckee603

Help with question 6 parts A and B. Thanks!

f=k delta l or f=ks whatever you use in your exam

k is 2.4x10^3 because its kilo

delta l or s is 0.15

f= (2.4x 10^3)(0.15)
f=360

because the block is falling it must have an acceleration equal to the gravitational acceleration therefore f=ma

we know that f=360
therefore ma=360
where a is 9.81
m=360/9.81
m=38kg

(method is right but answer could be wrong)

No clue on the next part sorry mate

Reply 3

NoahMal

17

Original post by sherv1360

energy of a spring = 1/2 kx^2 we have x which is compression/extension and k=2.4 work out energy which equals 0.27 (convert cm into m and the kN/M into N/M) you get e=0.27 joules. the change in height is = 0.6 -0.1=0.5 You know that E=MGH soe equate the 2 equations giving you
MGH = 0.27 so m=0.27/(9.81X0.5)

Im not sure what you did there mate but to me what I did makes more sense

TBH at the end of the day were all ****ed for physics no matter what

Reply 4

jmckee603

OP

2

Awesome thanks for the help! Any suggestions for part B?

Reply 5

Lauren-x-

13

Original post by sherv1360

energy of a spring = 1/2 kx^2 we have x which is compression/extension and k=2.4 work out energy which equals 0.27 (convert cm into m and the kN/M into N/M) you get e=0.27 joules. the change in height is = 0.6 -0.1=0.5 You know that E=MGH soe equate the 2 equations giving you
MGH = 0.27 so m=0.27/(9.81X0.5)