5. What is the velocity if 25 waves pass by a given point in 10 seconds and the wavelength is 50 cm?

A. 12.5 cm per second
B. 15 cm per second
C. 2.5 cm per second
D. 125 cm per second



Answer :

To solve the problem of finding the velocity of waves, we need to follow these steps:

1. Determine the frequency of the waves:
- Frequency is defined as the number of waves that pass a given point in a specific amount of time.
- The formula to calculate frequency is:
[tex]\[ \text{Frequency} = \frac{\text{Number of waves}}{\text{Time (seconds)}} \][/tex]
- Given that the number of waves is 25 and the time is 10 seconds, we can substitute these values into the formula:
[tex]\[ \text{Frequency} = \frac{25}{10} \][/tex]
- By performing the division, we get:
[tex]\[ \text{Frequency} = 2.5 \, \text{waves per second} \][/tex]

2. Calculate the velocity of the waves:
- The velocity of a wave is calculated by multiplying the frequency by the wavelength.
- The formula to calculate velocity is:
[tex]\[ \text{Velocity} = \text{Frequency} \times \text{Wavelength} \][/tex]
- Given that the frequency is 2.5 waves per second and the wavelength is 50 cm, we can substitute these values into the formula:
[tex]\[ \text{Velocity} = 2.5 \, \text{waves per second} \times 50 \, \text{cm} \][/tex]
- By performing the multiplication, we get:
[tex]\[ \text{Velocity} = 125 \, \text{cm per second} \][/tex]

Therefore, the velocity of the waves is [tex]\( \boxed{125 \text{ cm per second}} \)[/tex]. This matches the last option provided in the question.