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The collar of negligible size has a mass of 0.25 kg and is attached to a spring having an unstretched length of 100 mm. If the collar is released from rest at A and travels along the smooth guide, determine its speed just before it strikes B. A 20kg mass weighs 20 kg on Earth(1.000 g). It weighs 7.52 kg on Mars(0.376g). And on Pluto (0.67g), where you are from, it weighs 1.34 kg. The mass remains the same.

• The Collar Has A Mass Of 20kg And Rests On The Smooth Rod
• The Collar Has A Mass Of 20kg And Slides Along The Smooth Rod

The ball D has a mass of 20 kg. If a force of F = 100 N is applied horizontally to the ring at A, determine the largest dimension d the force in cable AC is zero.

A store's sign has a mass of 20kg and is 3.0m long. It is uniform, so it's center of gravity is at the center of the sign. It is supported horizontally by a small loose bolt attached to the wall at one end and by a wire at the other end, as shown in the figure. Two children sit on a seesaw. One has a mass of 20 kg and sits 1.0 m from the pivot point. If the other children has a mass of 23 kg, how far must she sit from the pivot to balance the seesaw?

Image from: Hibbeler, R. C., S. C. Fan, Kai Beng. Yap, and Peter Schiavone. Statics: Mechanics for Engineers. Singapore: Pearson, 2013.

The Collar Has A Mass Of 20kg And Rests On The Smooth Rod

Let us write our equations of equilibrium.

rightarrow ^+sum text{F}_text{x},=,0
100,-,F_{AB}text{cos}theta,=,0

F_{AB},=,dfrac{100}{text{cos}theta}

F_{AB}text{sin}theta,-,196.2,=,0

Substitute the isolated value of F_{AB} from

left(dfrac{100}{text{cos}theta}right)text{sin}theta,=,196.2
(Simplify)

dfrac{text{sin}theta}{text{cos}theta},=,1.962

text{tan}theta,=,1.962

theta,=,text{tan}^{-1}(1.962)
theta,=,63^0

To figure out d, we can use trigonometry. We can write the following:

text{tan},(63^0),=,dfrac{(1.5,+,d)}{2}

d,=,2.42 m

If, you wanted, you can also figure out F_{AB} by substituting the value of theta we found back into

The Collar Has A Mass Of 20kg And Slides Along The Smooth Rod

eq.1.F_{AB},=,dfrac{100}{text{cos},(63^0)}

F_{AB},=,220 N