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3 years ago

The throwing back by a wall or barrier of a sound wave without absorbing it. * 1 point

Physics

1 answer:

Semenov [28]3 years ago

8 0

Answer:Reflection

Explanation:

The throwing back of a sound wave without absorbing it is called reflection

In acoustic reflection of sound is termed as echo i.e. sound arrived at the listener after a particular delay depending upon the position of barrier to the observer.

The reflection of sound is used in many devices like megaphone, trumpets, etc. It is also used in auditorium such that the ceiling of the auditorium is curved for multiple reflections of sound so that sound can be reached at every corner of the auditorium.

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The slowest type of mass movement, Which involves the lifting and contracting of soil particles overtime, is called

finlep [7]

Answer should be Creep.

3 0

3 years ago

A ball is projected at an initial speed of 20.0 meter per second making an angle of 45.0 with horizontal. What is the maximum he

Andrew [12]

Answer:

10.2 metres

Explanation:

Given that a ball is projected at an initial speed of 20.0 meter per second making an angle of 45.0 with horizontal. What is the maximum height it will reach?

Solution

To get the maximum height, let us use the formula

V^2 = U^2 sin^2ø - 2gH

At maximum height V = 0

U^2 sin^2ø = 2gH

Substitute all the parameters into the formula

20^2 ( sin 45 )^2 = 2 × 9.8 × H

400 × 0.5 = 19.6 H

Make H the subject of formula

H = 200 / 19.6

H = 10.204 metres.

Therefore, the maximum height reached by the projected ball is 10.2 metres.

5 0

3 years ago

The wheel of a bicycle with a radius of 0.85 m is traveling at a speed of 5.0 m/s. Calculate its angular speed.

PIT_PIT [208]

Answer:

Explanation:

Angular speed=velocity/radius

5/0.85=5.9

7 0

2 years ago

Newton established his three laws of motion to do what?

marshall27 [118]

Newton established his three laws of motion to understand the motion of objects in a systematic way [ same thing as all Scientists did for human's curiosity ].

His three laws of motion are as follows:

First Law: - An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.

Second Law: - The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.

Third Law: - For every action, there is an equal and opposite reaction

Hope this helps!

5 0

3 years ago

A 1100 kg car rounds a curve of radius 68 m banked at an angle of 16 degrees. If the car is traveling at 95 km/h, will a frictio

Mariulka [41]

Answer:

Yes. Towards the center. 8210 N.

Explanation:

Let's first investigate the free-body diagram of the car. The weight of the car has two components: x-direction: towards the center of the curve and y-direction: towards the ground. Note that the ground is not perpendicular to the surface of the Earth is inclined 16 degrees.

In order to find whether the car slides off the road, we should use Newton's Second Law in the direction of x: F = ma.

The net force is equal to $F = \frac{mv^2}{R} = \frac{1100\times (26.3)^2}{68} = 1.1\times 10^4~N$

Note that 95 km/h is equal to 26.3 m/s.

This is the centripetal force and equal to the x-component of the applied force.

$F = mg\sin(16) = 1100(9.8)\sin(16) = 2.97\times10^3$

As can be seen from above, the two forces are not equal to each other. This means that a friction force is needed towards the center of the curve.

The amount of the friction force should be $8.21\times 10^3~N$

Qualitatively, on a banked curve, a car is thrown off the road if it is moving fast. However, if the road has enough friction, then the car stays on the road and move safely. Since the car intends to slide off the road, then the static friction between the tires and the road must be towards the center in order to keep the car in the road.

5 0

4 years ago