A student is comparing the speed of sound in air and water. She measures the frequency, f, and wavelength, λ, of sound waves in both air and water. The results are shown in the following table. Based on her data, how does the speed of sound in water compare to the speed of sound in air? A. The speed of sound through water is 4.3 times faster than sound through air.
B. The speed of sound through water is 2.6 times slower than sound through air.
C. The speed of sound through water is 8.4 times faster than sound through air.
D. The speed of sound through air is approximately equal to the speed of sound through water.

Option A. The speed of sound through water is 4.3 times faster than sound through air.

Explanation:

To answer the question correctly, we shall determine the speed of the wave in both cases. This is illustrated below:

For Air:

Frequency (fₐ) = 195 Hz

Wavelength (λₐ) = 1.76 m

Velocity (vₐ) =?

vₐ = λₐfₐ

vₐ = 1.76 × 195

vₐ = 343.2 m/s

For Water:

Frequency (fᵥᵥ) = 195 Hz

Wavelength (λᵥᵥ) = 7.6 m

Velocity (vᵥᵥ) =?

vᵥᵥ = λᵥᵥfᵥᵥ

vᵥᵥ = 7.6 × 195

vᵥᵥ = 1482 m/s

Finally, we shall compare the speed in water to that of air. This can be obtained as follow:

Velocity in air (vₐ) = 343.2 m/s

Velocity in water (vᵥᵥ) = 1482 m/s

Water : Air

vᵥᵥ : vₐ =>

vᵥᵥ / vₐ = 1482 / 343.2

vᵥᵥ / vₐ = 4.3

Cross multiply

vᵥᵥ = 4.3 × vₐ

Thus, the speed in water is 4.3 times the speed in air.

Option A gives the correct answer to the question.

b.a device that inputs heat into a cool object

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.