# Statics Example

Topics: Mass, Force, Friction Pages: 3 (448 words) Published: February 8, 2011
Statics

1.A uniform flexible steel cable of mass m is suspended between two equal elevation
points as shown in the figure below.

(a)Determine the tension in the cable(i)at the points of attachment,[[pic]]
(ii)at its lowest point in terms of (. [[pic]]
b) What is the direction of the tension force in each case?

2.Two guy wires run from the top of a pole 2.6 m tall that supports a volleyball net. The
two wires are anchored to the ground 2.0 m apart and each is 2.0 m from the pole as
shown below. The tension in each wire is 95 N.

(a)What is the magnitude the force acting on the top of the pole by the wires?[181 N]
(b)What is the tension in the net, assumed horizontal and attached at the top
of the pole.[100 N]

3.A man wants to push a lamp of mass 7.5 kg across the floor as shown below.

(a)Assuming the person pushes at a height 0.60 m above the floor and the frictional
force between the base of the lamp and the floor is 15 N, determine whether the
lamp will slide or tip over.
(b)Calculate the maximum height above the floor at which the person can push the
lamp so that it slides rather than tips.[0.5 m]

4.A 5.0 m long ladder leans against a wall at a point 4.0 m above the ground as shown
below. The ladder is uniform and has mass 12.0 kg. Assuming the wall is frictionless
(but the ground is not),

(a)determine the force exerted on the ladder
(i)by the wall,[45 N, normal to the wall]
(ii)by the ground.[128 N, 69.4o to the ground]
(b)A painter of mass 60.0 kg slowly climbs up the ladder. The ladder begins to slip at
its base when the painter is 70 % of the way up the length of the ladder, what is the
limiting static friction between the ladder and the floor?[360 N]

5.A shop sign weighing 100 N is supported by a uniform beam secured to the wall by a
hinge as shown below. The beam weighs 50 N.

(a)Calculate the tension in the cable.[291N]
(b)What are the...