# Geometry

A construction crew wants to hoist a heavy
beam so that it is standing up straight. They
tie a rope to the beam, secure the base, and
pull the rope through a pulley to raise one
end of the beam from the ground. When
the beam makes an angle of 40 degrees with the
ground, the top of the beam is 8 ft above
the ground.
Th e construction site has some telephone
wires crossing it. Th e workers are
concerned that the beam may hit the wires.
When the beam makes an angle of 60 degrees with
the ground, the wires are 2 ft above the top
of the beam. Will the beam clear the wires
on its way to standing up straight?
Can I please get help with how to specifically solve this? I am very confused and I need step by step guidance.

1. 👍
2. 👎
3. 👁
1. As the problem is stated, of course they will because as it rises the horizontal distance from the pivot point at the ground decreases. If the wires are exactly above the tip of the bean at 60 deg, then they will be closer to the pivot point at more than 60deg
Therefore I assume you have left out the horizontal overlap at 60 degrees and you need to figure out haw far back the beam moves as it pivots up those last two feet

at 8 feet up
sin 40 = 8/length of beam
so L = 12.45 ft length

then at 60 degrees
sin 60 = h/12.45
h = 10.78 high
and horizontal distance is
12.45 cos 60 = 6.23

now at h = 2+10.78 = 12.78
BUT that is higher than the beam is long :)
No way it will hit the wires.

1. 👍
2. 👎
2. I think the answer is 12.78. But I'm not 100% honest.

1. 👍
2. 👎

## Similar Questions

1. ### Math

A construction crew wants to hoist a heavy beam so that it is standing up straight. They tie a rope to the beam, secure the base, and pull the rope through a pulley to raise one end of the beam from the ground. When the beam makes

2. ### Calculus

A radar antenna is located on a ship that is 4km from a straight shore. It is rotating at 32rev/min. How fast does the radar beam sweep along the shore when the angle between the beam and the shortest distance to the shore is

3. ### Math/Physics

A block-and-tackle pulley hoist is suspended in a warehouse by ropes of lengths 2 m and 3 m. The hoist weighs 340 N. The ropes, fastened at different heights, make angles of 50° and 38° with the horizontal. Find the tension in

4. ### physics

An 76 kg construction worker sits down 2.0 m from the end of a 1440 kg steel beam to eat his lunch. The cable supporting the beam is rated at 15,000 N. Should the worker be worried? Determine the tension in the cable. i.imgur.

1. ### Physics

A 4.00-m-long, 500 kg steel beam extends horizontally from the point where it has been bolted to the framework of a new building under construction. A 70.0 kg construction worker stands at the far end of the beam. What is the

2. ### help asap plz

A 15-person road crew is scheduled to finish repairing a highway in 12 days. On the morning of the fifth day, several new workers join the crew and, together, they complete the remaining repairs in 6 days. How many new workers

3. ### math

The weight W that a horizontal beam can support varies inversely as the length L of the beam. Suppose that a 4-m beam can support 1000 kg. How many kilograms can a 17-m beam​ support?

4. ### math

A construction crew has just finished building a road. The road is 10 kilometers long. If the crew worked for 4 2/3 days, how many kilometers of road did they build each day? (Assume they built the same amount each day.) Write

1. ### strength of materials

1.a concentrated load p is applied at the end of cantilever.the crosssection of the beam is a square of side "a" and with a hole of diameter "a/2" then deflection at the tip of beam is?lengh of beam is L.

2. ### physics

In Fig. 12-51, uniform beams A and B are attached to a wall with hinges and loosely bolted together. Beam A has length LA = 2.55 m and mass 49.0 kg; beam B has mass 69.0 kg. The two hinge points are separated by distance d = 1.86

3. ### Math

A crew is made up of 8 men; the rest are women. 66 and 2 thirds of the crew are men. How many people are in the crew

4. ### college algebra

the following rational function gives the number of days it would take two construction crews, working together, to frame a house that crew 1 (working alone)could complete in t days and crew 2 (working alone) could complete in t+3