Answer:
900 cm/s or 9 m/s.
Explanation:
Data obtained from the question include the following:
Length (L) = 30 cm
frequency (f) = 60 Hz
Velocity (v) =.?
Next, we shall determine the wavelength (λ).
This is illustrated below:
Since the wave have 4 node, the wavelength of the wave will be:
λ = 2L/4
Length (L) = 30 cm
wavelength (λ) =.?
λ = 2L/4
λ = 2×30/4
λ = 60/4
λ = 15 cm
Therefore, the wavelength (λ) is 15 cm
Now, we can obtain the speed of the wave as follow:
wavelength (λ) = 15 cm
frequency (f) = 60 Hz
Velocity (v) =.?
v = λf
v = 15 × 60
v = 900 cm/s
Thus, converting 900 cm/s to m/s
We have:
100 cm/s = 1 m/s
900 cm/s = 900/100 = 9 m/s
Therefore, the speed of the wave is 900 cm/s or 9 m/s.
Answer:

Explanation:
= Force on one side of the door by first waiter = 257 N
= Force on other side of the door by second waiter
= distance of first force by first waiter from hinge = 0.567 m
= distance of second force by second waiter from hinge = 0.529 m
Since the door does not move. hence the door is in equilibrium
Using equilibrium of torque by force applied by each waiter

Answer:
Scientific knowledge is used to create new technologies. New technologies often allow scientists to explore nature in different ways and make new discoveries.
Explanation:
An average facility manager can build one new facility
during his or her career.
<span>A </span>facilities manager<span> is the ultimate organiser, making sure that a
workplace meets the needs of employees by managing all of the required
services. In this job, you will be responsible for the </span>management<span> of services and processes that support the core
business of an organisation.</span>
Answer:
The coefficient of performance for the cycle is 2.33.
Explanation:
Given that,
Output energy 
Work done 
We need to calculate the coefficient of performance
Using formula of the coefficient of performance

We need to calculate the 

Put the value into the formula



Now put the value of
into the formula of COP


Hence, The coefficient of performance for the cycle is 2.33.