Question

A 16.0-m uniform ladder weighing 490 N rests against a frictionless wall. The ladder makes a 61.0° angle with the horizontal.

(a) Find the horizontal and vertical forces the ground exerts on the base of the ladder when an 820-N firefighter has climbed 4.30 m along the ladder from the bottom.

Horizontal Force

magnitude | __N |

direction | - towards the wall or away from the wall? |

Vertical Force

magnitude | N |

direction | up or down? |

(b) If the ladder is just on the verge of slipping when the
firefighter is 9.40 m from the bottom, what is the coefficient of
static friction between ladder and ground?

Answer #1

Sum moments about the floor
contact to find the wall reaction horizontal force.

Rw[16sin61] - 490[(16/2)cos61] - 820[4.3cos61] = 0

Rw = 258 N

Sum horizontal forces to zero shows that the horizontal floor
reaction is 258 N toward the wall

Sum vertical forces to zero to find the floor vertical force

Fv - 490 - 820 = 0

Fv = 1310 N upward

b) Using the same logic to find the horizontal reactions when the
firefighter is higher

Rw[16sin61] - 490[(16/2)cos61] - 820[9.4cos61] = 0

Rw = Fh = 402.8 N

The vertical reaction remains the same

Fv = 1310 N upward

coefficient of friction ? is the ratio of the maximum horizontal
force to vertical force

? = Fh / Fv

? = 402.8 / 1310

? = 0.30....Answer

Hope It will help You please rate the answer.

A 16.0-m uniform ladder weighing 490 N rests against a
frictionless wall. The ladder makes a 55.0° angle with the
horizontal.
(a) Find the horizontal and vertical forces the ground exerts on
the base of the ladder when an 820-N firefighter has climbed 4.20 m
along the ladder from the bottom.
Horizontal Force
magnitude
N
direction
---Select--- towards the wall away from the wall
Vertical Force
magnitude
N
direction
---Select--- up down
(b) If the ladder is just on the...

A 16.0-m uniform ladder weighing 490 N rests against a
frictionless wall. The ladder makes a 57.0° angle with the
horizontal.
(a) Find the horizontal and vertical forces the ground exerts on
the base of the ladder when an 850-N firefighter has climbed 4.20 m
along the ladder from the bottom.
Horizontal Force
magnitude
direction
Vertical Force
magnitude
direction
(b) If the ladder is just on the verge of slipping when the
firefighter is 9.10 m from the bottom, what...

A ladder having a uniform density and a mass m rests
against a frictionless vertical wall, making angle 49.0° with the
horizontal. The lower end rests on a flat surface where the
coefficient of static friction is µs = 0.410. A window
cleaner with mass M = 2m attempts to climb the
ladder. Given a ladder length of L, what fraction of the
length of the ladder (x / L) will the worker have reached
when the ladder begins to...

A ladder having a uniform density and a mass m rests
against a frictionless vertical wall, making angle 50.0° with the
horizontal. The lower end rests on a flat surface where the
coefficient of static friction is µs = 0.420. A window
cleaner with mass M = 2m attempts to climb the
ladder. Given a ladder length of L, what fraction of the
length of the ladder (x / L) will the worker have reached
when the ladder begins to...

A uniform ladder rests against a frictionless wall at an angle
of
θ = 50.0°
with respect to the ground. If the weight of the ladder is
WL = 250 N,
the length is
L = 9.0 m,
and the coefficient of static friction between the ladder and
the ground is
μs = 0.65,
determine the distance a man with a weight of
WM = 800 N
can climb along the ladder before the ladder begins to slip.

A uniform ladder rests against a frictionless wall at an angle
of θ = 54.0° with respect to the ground. If the weight of the
ladder is WL = 240 N, the length is L = 7.0 m, and the coefficient
of static friction between the ladder and the ground is μs = 0.55,
determine the distance a man with a weight of WM = 875 N can climb
along the ladder before the ladder begins to slip
. ______m

An 8.00 m, 201 N uniform ladder rests against a smooth wall. The
coefficient of static friction between the ladder and the ground is
0.600, and the ladder makes a 50.0o angle with the
ground. How far up the ladder can an 801N person climb before the
ladder begins to slip?

A uniform ladder has a mass of 16.0 kg and a length of 8.50 m.It
stands on the ground and leans against a vertical wall, making an
angle of 62 degrees with the ground. The friction between the wall
and the ladder is not significant.What is the smallest force of
friction between the ladder and the ground that will prevent the
ladder from slipping?

A uniform ladder of length l and mass m rests against a smooth,
vertical wall. The coefficient of static friction between ladder
and ground is 0.35. Find the minimum angle at which the ladder does
not slip. (Consider the torques about an axis perpendicular to the
page through O)

A uniform ladder whose length is 5.0 m and whose weight is 400 N
leans against a frictionless vertical wall. The coefficient of
static friction between the level ground and the foot of the ladder
is 0.46. What is the greatest distance the foot of the ladder can
be placed from the base of the wall without the ladder immediately
slipping?

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 7 minutes ago

asked 12 minutes ago

asked 13 minutes ago

asked 26 minutes ago

asked 28 minutes ago

asked 28 minutes ago

asked 28 minutes ago

asked 30 minutes ago

asked 32 minutes ago

asked 43 minutes ago

asked 44 minutes ago

asked 46 minutes ago