Answer:
3.At equilibrium, its instantaneous velocity is at maximum
Explanation:
The motion of a mass on the end of a spring is a simple harmonic motion. In a simple harmonic motion, the total mechanical energy of the system is constant, and it is sum of the elastic potential energy (U) and the kinetic energy of the mass (K):

where
k is the spring constant
x is the displacement of the spring from equilibrium
m is the mass
v is the speed
As we see from the formula, since the total energy E is constant, when the displacement (x) increases, the speed (v) increases, and viceversa. Therefore, when the mass is at its equilibrium position (which corresponds to x=0), the velocity of the mass will be maximum.
The answer is d hope this helps
Order to ensure a message is understood requires all four option is needed.
The option will be D.All of the above.
<h3>
What is a good communication skill?</h3>
- The sender is the person who is trying to communicate a message.
- The challenge is that since the receiver’s education and experience may be very different from the sender's, words often have different meanings.
- While we may carefully choose the words to speak, words alone represent a small percentage.
- communication is only verbal the most important element of communication
- When encountering a noise, take steps to reduce the distraction.
Learn more about speaking skills here:-brainly.com/question/25645043
#SPJ2
Answer:
(a) 
(b) 
Explanation:
Hello.
(a) In this case, since the initial volume is 18.5 dm³ and the final volume is 21 dm³ (18.5 +2.5), we can compute the work at constant pressure as shown below:

Which is negative as it expands against the given pressure.
(b) Moreover, of the process is carried out reversibly, the pressure can change, therefore, we need to compute the work via:

Whereas the moles are computed from the given mass of argon:

Thus, the work is:

Regards.