Answer:
t = 2s
Explanation:
When you're looking for instantaneous portions of a graph, of any sort really, it means you're observing a rate at a single point in time [or possibly some other variable]. It's sorta like a snapshot of a rate as opposed to an average rate over an interval. After choosing this rate we'll typically draw a straight, tangent line through it to indicate it's slope. (Tangent lines are just lines that only touch a single point on a graph or shape.)
Another thing to take note of are the values of the graph's major axes. The "y-axis" corresponds to velocity in meters per second, while the "x-axis" corresponds to time in seconds. Normally when relating the two we put "y" over the "x" and say that at any point there are "y[units]" per "x[units]". Though with instantaneous rates, we say the value of "x" is "1"; for reasons I can try to further explain later if you'd like.
With the above information in mind we can turn our attention to your graph. You're told to find the point on this graph where the instantaneous rate of acceleration is -2 m/s². The only place where the graph reflects an instantaneous rate of -2m/s² is at t = 2s. At t = 2, the rate comes out to (2[m/s]/1s), which simplifies to 2m/s². If you then draw the tangent line through the point, you'll find that the line is decreasing (going down from left to right) which means that the instantaneous rate is negative. 
So at t = 2s, we have an instantaneous acceleration of -2m/s².
 
        
             
        
        
        
Answer:
a. the magnitude of the force experienced by the muon is 2.55 × 10⁻¹⁹N
b.  this force compare to the weight of the muon; the force is 1.38 × 10⁸ greater than muon
Explanation:
F= ma
v²=u² -2aS
(1.56 ✕ 10⁶)²=(2.40 ✕ 10⁶)²-2a(1220)
a=1.36×10⁹m/s²
recall
F=ma
F = 1.88 ✕ 10⁻²⁸ kg × 1.36×10⁹m/s²
F= 2.55 × 10⁻¹⁹N
the magnitude of the force experienced by the muon is 2.55 × 10⁻¹⁹N
b.  this force compare to the weight of the muon
F/mg= 2.55 × 10⁻¹⁹/ (1.88 ✕ 10⁻²⁸ × 9.8)
= 1.38 × 10⁸
 
        
             
        
        
        
Answer:
The atomic number of Aluminum is "13"!
Explanation:
The 27 means the atomic mass is 27 . The number of protons plus the number of neutrons is 27. That means the number of neutrons is 27–13=14. Number of neutrons depends on the isotopic form of aluminium.
 
        
             
        
        
        
The water tank waves are transverse waves while the sound waves are longitudinal waves.
<h3>What is a wave?</h3>
A wave is a disturbance along a medium which transfers energy. We know that the water tank waves are transverse waves while the sound waves are longitudinal waves.
The difference between the two is that in the water waves, the direction of the wave motion is perpendicular to the disturbance while in the sound waves, the the direction of the wave motion is parallel to the disturbance.
Learn more about waves:brainly.com/question/16263433?
#SPJ1 
 
        
             
        
        
        
Answer: D. it has been demonstrated to be without exception under certain stated conditions.
Explanation:
A <u>Law</u> is an affirmation (something established) based on repeated long-term observation of a phenomenon that has been studied and verified.  
That is: A law is present in all known theories and therefore is considered universal. In addition, a law can not be refuted, nor changed, because its precepts have been proven through various studies.  
<u>Unlike theory</u>, which is the set of rules and principles that describe and explain a particular phenomenon and <u>is subject to changes as new evidence emerges that gives meaning to it.  </u>
Then, based on what is explained above, the law of universal gravitation is a statement that exists because it was rigorously tested and verified, therefore it can not be refuted.