1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Tomtit [17]
3 years ago
5

A 5 meter long ladder leans against a wall. The bottom of the ladder slides away from the wall at the constant rate of 1 3 m/s.

How fast is the angle θ between the ground and the ladder changing when the bottom of the ladder is is 3 meters from the wall?

Physics
1 answer:
Oksana_A [137]3 years ago
5 0

Answer:9.75 m/s

Explanation:

Given

Length of ladder (L)=5 m

Foot the ladder is moving away with speed of \frac{\mathrm{d} x}{\mathrm{d} t}=13 m/s

From diagram

x^2+y^2=L^2------1

at x=3

y^2=25-9=16

y=4 m

Now differentiating equation 1 w.r.t time

2x\frac{\mathrm{d} x}{\mathrm{d} t}+2y\frac{\mathrm{d} y}{\mathrm{d} t}=0

x\frac{\mathrm{d} x}{\mathrm{d} t}=-y\frac{\mathrm{d} y}{\mathrm{d} t}

3\times 13=-4\times \frac{\mathrm{d} y}{\mathrm{d} t}

\frac{\mathrm{d} y}{\mathrm{d} t}=-\frac{3\times 13}{4}=-9.75 m/s

negative indicates distance is decreasing with time

You might be interested in
A student drops two metallic objects into a 120-g steel con- tainer holding 150 g of water at 25°C. One object is a 200-g cube o
marissa [1.9K]

Answer:

The mass of the aluminum chunk is 258 g

Explanation:

Given;

mass of steel container =  120-g

mass of water = 150 g

initial temperature of water, = 25°C

mass of copper cube, M_{cu} = 200 g

initial temperature of the copper cube, T_c_u = 85°C

initial temperature of the aluminum chunk T_A_l = 5.0°C

Neglecting heat loss, heat exchanged by the two metallic objects is the same since initial temperature is equal to final temperature of water.

M_{Al}C_{Al} \delta T_{Al} = M_{cu}C_{cu} \delta T_{cu}

where;

C_{AL} is specific heat capacity of aluminum

\delta T_{Al} is change in temperature of aluminum

C_c_u is the specific heat capacity of copper

\delta T_c_u is the change in temperature of copper

M_{Al}C_{Al} \delta T_{Al} = M_{cu}C_{cu} \delta T_{cu} \\\\M_{Al} = \frac{M_{cu}C_{cu} \delta T_{cu}}{C_{Al} \delta T_{Al}} \\\\M_{Al} = \frac{0.2*387*60}{900*20} = 0.258 \ kg

Therefore, the mass of the aluminum chunk is 258 g

7 0
3 years ago
What happens to its surface temperature as a star changes color from red to blue
MAVERICK [17]
The surface temperature of the star increases when it changes its colour changes from red to blue.
Blue>white>yellow>orange>red
The given series is the temperature decreasing order of stars. Now our sun is considered as a yellow star.
5 0
3 years ago
Complete the sentence to describe what a wave is and what it does.
sweet-ann [11.9K]

Answer:

A wave is a vibration in mediun tbat carries energy from one place to another.

Explanation:

7 0
3 years ago
Read 2 more answers
What measures the distance between two consecutive crests of a wave?
Marina86 [1]
Answer A is incorrect
A crest is just one point. It is not the distance between 2 crests.

B  is incorrect
A trough is just 1 point. It is not the distance between 2 troughs.

C is incorrect.
the amplitude measures the height of a crest from the middle of the wave to the crest (or trough).

D is the correct answer. That is the distance between 2 crests or 2 troughs 
8 0
3 years ago
The acceleration due to gravity on the Moon's surface is
Molodets [167]

Answer:

50 lb

Explanation:

Given,

The weight of astronaut's life support backpack on Earth (w) = 300 lb

Acceleration due to gravity on Earth (g) = 9.8 m/s²

Acceleration due to gravity on Moon = g'

g'=\frac{g}{6}

We know that weight of an object on Earth is,

w = m\times g

m = \frac{w}{g}

Similarly, weight on Moon will be

w' = m\times g'

w' = \frac{w}{g}\times\frac{g}{6}

w' = \frac{300}{6}

w' = 50

Thus the astronaut's life support backpack will weigh 50 lb on Moon.

7 0
3 years ago
Other questions:
  • 2. What is the least possible error encountered
    8·2 answers
  • Thoroughly explain how to balance this chemical equation.
    15·1 answer
  • A cannon is mounted on a cart which sits on the ground, supported by frictionless wheels. The mass of the cannon and cart is 4.6
    13·2 answers
  • Match the description to the property.
    8·1 answer
  • If the mass of a ball B is 1 kilogram and it’s speed is 1 m/sec. the mass and the speed of ball A is three times the mass and sp
    11·2 answers
  • A pilot in a small plane encounters shifting winds. He flies 26.0 km northeast, then 45.0 km due north. From this point, he flie
    11·1 answer
  • What happens to some of the sun's energy that does not reach the earth's surface?
    9·1 answer
  • Newton discovered that gravity behaves differently in space than it does on Earth. true or false?
    12·1 answer
  • How does a sound wave transfer energy to your ears?
    12·1 answer
  • A cannonball is fired vertically upwards at 100.0 m/s a) How long will it take to return to the cannon? b) what is it's maximum
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!