Webassign Assignment #5

Problem 8 in text, 5 on webassign.

Two horizontal forces act on a 1.3kg disk

Force one is in the negative x direction. -1î

Force 2 has a magnitude of 9N

3m/s•s

maî + maj

F1=-1i

F2 = 9cos∂i+ 9sin∂j                                                                        The key here is that you’re looking for the x component only.

mai = -1 + 9cos∂

1.3•3 = -1+9cos∂

=57.013º

NOTE: In a case where you have a negative F1, you'll have to do 180 minus your angle.

1. 9kg monkey goes up rope, frictionless tree limb

PHYSICS MONKEY

Forces on monkey: Gravity (mg), Monkey pulling on rope, force of rope on monkey F=T

Up is positive

Forces on package: Gravity (mg), Tension up, normal force

Package is 14kg

acceleration is up

T - 9g = 9•a

T - 14g + F(normal) = m(package)a

a) F(normal) = 0, a(package) = 0

T -14g = 0

T=137.34

Monkey must have acceleration of 5.45

b) acceleration after? F(normal) is still zero. a(package) is a number

a(package) = -a(monkey)

a(monkey)= 5/23•g should be 2.1326


EDIT: Awesome, I can upload my notes directly to the blog.