All categories

3 years ago

Assume a change at the source of sound reduces the wavelength of a sound wave in air by a factor of 3.

Physics

1 answer:

noname [10]3 years ago

8 0

Explanation:

The speed of a wave is given by :

$v=f\lambda$ ......(1)

(i) Here, the wavelength of a sound wave in air reduces by a factor of 3. Equation (1) becomes :

$\lambda=\dfrac{v}{f}$

Wavelength and frequency are inversely proportional to each other. So, if wavelength of a sound wave in air reduces by a factor of 3, then the frequency will increases by a factor of 3.

(ii) It remains the same.

You might be interested in

Choose whether each of the following statements is true or false. In order to move a massive crate sitting on the floor, the for

velikii [3]

Answer:

Explanation:

1. False

The force you apply on crate is equal and opposite to the force that crate applies on you by Newton's third law of motion.

The force must over come the static frictional force between the crate and the floor.

2. True

The object can move along another direction than the direction of net force. For example, when a car slows down, the net force is opposite to the direction of motion.

3. True

An object moving at constant velocity has zero net force acting on it.

4. False

An object at rest has forces acting on it but the summation of all the forces is zero i.e. the net force is zero.

6 0

3 years ago

A baseball player friend of yours wants to determine his pitching speed. You have him stand on a ledge and throw the ball horizo

Alla [95]

Answer:

$v_{ox}= 19.6\ m/s$

Explanation:

Data provided in the question:

Height above the ground, H= 5.0m

Range of the ball, R= 20 m

Initial horizontal velocity = $v_{ox}$

Initial vertical velocity= $v_{oy}$ (Since ball was thrown horizontally only)

Acceleration acting horizontally, $a_x$ = 0 m/s² [ Since no acceleration acts horizontally) ]

Vertical Acceleration, $a_y$ = 9.8 m/s² (Since only gravity acts on it)

Let 't' be the time taken to reach ground

Therefore, using equations of motion, we have

$H= v_{oy}t+\frac{1}{2}a_yt^2$

$5= (0)t+\frac{1}{2}(9.8)t^2$

$t= \frac{10}{9.8}=1.02 s$

Then using Equations of motion for horizontal motion,

$R= v_{ox}t+\frac{1}{2}a_xt^2$

$20= v_{ox}(1.02)+\frac{1}{2}(0)(1.02)^2$

$v_{ox}= 19.6\ m/s$

4 0

3 years ago

17. Which of the following is NOT a testable

Artemon [7]

Answer:

c. testing student opinions

Explanation:

opinions aren't factual and they would not aide an experiment if it wasn't for a social experiment.

7 0

2 years ago

When t= 1 a stone B is thrown vertically upwards from ground level with speed 5ms (ii) find t when a and b collide

Ksju [112]

Answer:

i don't know if this is good for you but

Explanation:

ignoring frictional air resistance (drag) the speed on return is the same as when it left the ground (5 m/s but in the opposite direction).

Note: this points out a good reason for not firing live bullets into the air..they will return somewhere and at the same speed.

However, if you take into account the atmospheric drag the reurn speed will be somewhat smaller (but in the case of a bullet, probably still lethal.) Drag depends on many factors and is difficult to calculate.

5 0

3 years ago

a 5 charge is locataed 1.25 m to the left of a -3 charge. What is the magnitude and direction of the electrostatic force on the

Alika [10]

Answer:

The force is 86.5×10^9 N towards the negative charge (to the right)

Explanation:

The electrostatic force on the charges is given by Coulomb's law;

F= Kq1q2/r^2

This an inverse square law.

F= electrostatic force on the charges

K= constant of Coulomb's law

q1 and q2= magnitude of the charges

Since K= 9.0×10^9Nm^2C^2

F= 9.0×10^9 × 5 × 3/(1.25)^2 = 135×10^9/1.56

F= 86.5×10^9 N

The force is 86.5×10^9 N towards the negative charge.

5 0

3 years ago