By listening to an orchestra, how can you determine that the speed of sound is the same for all frequencies?

Scientists estimate the age of the universe to be (1 point)

Nesterboy [21]

12-15 billion years i think

4 0

3 years ago

Elect the correct answer. Two identical projectiles, A and B, are launched with the same initial velocity, but the angle of laun

allsm [11]

Answer:

A. The range of A and B are equal.

Explanation:

Let u be the initial speed of both the projectile.

The gravitational force acting in the projectile is in the downward direction, sp the speed of the projectile in the horizontal direction remains constant and equals to the initial horizontal speed.

For projectile, a projectile having initial velocity u at an angle \theta with the horizontal direction,

The speed in the horizontal direction $= u\cos\theta$

and the speed in the vertical direction is $= u\sin\theta$ upward.

For A:

The speed in the horizontal direction $= u\cos75^{\circ}$

and the speed in the vertical direction is $= u\sin75^{\circ}$ upward.

For B:

The speed in the horizontal direction $= u\cos15^{\circ}$

and the speed in the vertical direction is $= u\sin15^{\circ}$ upward.

Let $t_A$ and $t_B$ are the time of flight for projectile A and B respectively.

As the range is the horizontal distance traveled by the projectile, so

The range for the projectile A $= u\cos75^{\circ}\times t_A\cdots(i)$

The range for the projectile B = $u\cos15^{\circ}\times t_B\cdots(ii)$

At the highest point, the vertical velocity is 0.

Bu using the equation of motion $v^2=u^2 +2a s.$

Here, the final velocity v=0, the initial velocity $u = u \sin \theta$ , h= vertical distance up to the highest point, and $a= -g$ (as per sign convention).

So, $s= \frac{u^2\sin^2 \theta}{2g}$

For projectile A: The maximum height attained.

$s_A= \frac{u^2\sin^2 75^{\circ}}{2g}$

For projectile B: The maximum height attained.

$s_B= \frac{u^2\sin^2 15^{\circ}}{2g}$

As $\sin^2 75^{\circ} > \sin^2 15^{\circ}$ , the height of A is attained by A is more than the heigHt attained by B.

Now, the times required to reach the highest point from the ground and again form the highest point to the ground are the same.

So, the total time of flight = 2 x (Time to reach the highest point)

In a similar way, by using the equation of motion v=u+at,

The time to reach the highest point $=\frac {u\sin\theta}{g}$

where g is the acceleration due to gravity.

So, the total time of flight

$= 2 \times \frac {u\sin\theta}{g}$

The total time of flight for A

$=2 \times \frac {u\sin75^{\circ}}{g}$

The total time of flight for A

$=2 \times \frac {u\sin15^{\circ}}{g}$

Now, from equations (i) and (ii),

The range for the projectile A =

$u\cos75^{\circ}\times \frac {2u\sin75^{\circ}}{g}=\frac {u^2 \sin 150^{\circ}}{g}= \frac {u^2 \sin 30^{\circ}}{g}$

The range for the projectile B =

$u\cos15^{\circ}\times \frac {2u\sin15^{\circ}}{g}=\frac {u^2 \sin 30^{\circ}}{g}.$

Both the projectile have the same range.

Hence, option (A) is correct.

7 0

3 years ago

Describe the atomic structure of hydrogen atom.

-Dominant- [34]

Answer and Explanation:

The hydrogen atom is an atom of hydrogen element.Hydrogen atoms contain one proton which has positive charge and one electron which has negative charge , so due to positive and negative charge present in the hydrogen atom its becomes neutral atom.In whole universe the hydrogen atom is found in most abundant. Electron and nucleus of the hydrogen atom is bound together with the help of coulomb force.

3 0

3 years ago

72. An object travels at a constant velocity of 15 m/s for 5.0 seconds. How far does

Gennadij [26K]

Answer: 125 m/s

Multiply 15 m/s by 5.0 minutes, because this will give you the product.

15 x 5.0 = 125.

Add the m/s sign to the 125. 125 m/s.

Answer = 125 m/s. Hope this helps!

8 0

3 years ago

An object is moving north at a constant speed. A force of 5 N begins to push the object east at the same moment that a force of

Svetllana [295]

Since both the forces are equal in magnitude (5N) and opposite in direction (one is toward the east and the other, the west), they'll cancel out each other, and the object will continue moving north

Hope this answered your question

7 0

3 years ago

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