A train's mass is 500 kg and it's acceleration is 5 m/s. What is the net force on the train

The trunk of a elephant may extend up to 2.2 m. It acts much like an organ pipe only open at one end when the elephant blows air

Talja [164]

Answer:

1) f = 38.63 Hz , 2) f = 115.9 Hz

Explanation:

The elephant's trunk can be approximated by a tube with a closed end, in pipes the closed ends correspond to nodes and the open ends to antinodes or bellies.

The expression for the wavelengths of this system is

4L = n λ

n = 1, 3, 5, 7 ...

also let's use the relationship between frequency and wavelength and wave speed

v = λ f

f = v / λ

f = v n / 4L

f = v / 4L n

1) the fundamental frequency occurs for n = 1

f = 340/4 2.2 1

f = 38.63 Hz

2) The first harmonic

n = 3

f = 340/4 2.2 3

f = 115.9 Hz

5 0

3 years ago

Jason drives uphill from home to school, averaging 20 miles per hour. On the way back, he drives back downhill from school to ho

r-ruslan [8.4K]

Answer:

Average velocity = 30 miles per hour

Explanation:

Given that

Velocity for uphill = 20 miles per hour

Velocity for downhill = 60 miles per hour

We know that

Distance = Velocity x time

Total distance = Average velocity x total time

Lets take distance from home to school is s

Time taken from home to school= s/20 hr

Time taken from school to home= s/60 hr

Total time =s/20+s/60

Total distance = Average velocity x total time

s + s = Average velocity x (s/20+s/60)

So average velocity = 30 miles per hour

6 0

3 years ago

Which of these is NOT an example of a reference direction?

Vikentia [17]

Answer:

A

Explanation:

8 0

4 years ago

The angle θ is slowly increased. Write an expression for the angle at which the block begins to move in terms of μs.

Reika [66]

Answer:

$tan \theta = \mu_s$

Explanation:

An object is at rest along a slope if the net force acting on it is zero. The equation of the forces along the direction parallel to the slope is:

$mg sin \theta - \mu_s R =0$ (1)

where

$mg sin \theta$ is the component of the weight parallel to the slope, with m being the mass of the object, g the acceleration of gravity, $\theta$ the angle of the slope

$\mu_s R$ is the frictional force, with $\mu_s$ being the coefficient of friction and R the normal reaction of the incline

The equation of the forces along the direction perpendicular to the slope is

$R-mg cos \theta = 0$

where

R is the normal reaction

$mg cos \theta$ is the component of the weight perpendicular to the slope

Solving for R,

$R=mg cos \theta$

And substituting into (1)

$mg sin \theta - \mu_s mg cos \theta = 0$

Re-arranging the equation,

$sin \theta = \mu_s cos \theta\\\rightarrow tan \theta = \mu_s$

This the condition at which the equilibrium holds: when the tangent of the angle becomes larger than the value of $\mu_s$ , the force of friction is no longer able to balance the component of the weight parallel to the slope, and so the object starts sliding down.

4 0

4 years ago

In a simulation on earth, an astronaut in his space suit climbs up a vertical ladder. On the moon, the same astronaut makes the

mr Goodwill [35]

Answer:

Gravitational potential energy of the astronaut will change by a greater amount on the earth

Explanation:

Gravitational potential energy is expressed by the formula;

GPE = mgh

This means that the gravitational potential energy is directly proportional to the gravity(g)

Now, from constant values, gravity of moon is 1.62 m/s² while gravity of the earth is 9.81 m/s².

This means that if we plug in the values of g on the earth and g on the moon, the potential energy on the earth would be greater than that of the moon

Thus, gravitational potential energy of the astronaut will change by a greater amount on the earth

8 0

3 years ago