Answer:
Explanation:
Ultrasonic waves are acoustic waves that are so high in frequency that humans can't hear them; however, infrasonic waves are sound waves that are lower in frequency than what humans can hear. A subsonic wave is a wave that is traveling slower than the speed of sound and a supersonic waves travels faster
Answer:
it cannot be considered a physical change because it occur from the chemical reaction.
Explanation:
because physical change is the change of the size,volume, density,flexibility. in other words its a change in the outer appearance or change in which we can see or feel without using a tool or a machine
hope it help just my opinion
Answer:
![=2.99\times10^9J](https://tex.z-dn.net/?f=%3D2.99%5Ctimes10%5E9J)
Explanation:
According to the question
net force F = 2.20×10^6 N
displacement ![S = 0.72\times10^3m](https://tex.z-dn.net/?f=S%20%3D%200.72%5Ctimes10%5E3m)
from figure , the horizontal forces are same in magnitude and opposite direction.
so , neglect these two forces.
we can take only vertical components of the force.
total force F' = F cos 19° + F cos 19°
= 2×F×cos 19° ................. (1
therefore , total work is
W = F'S
= (2F cos19)×S
![= (2)(2.20\times10^6 N)cos19° (0.720\times10^3 m)](https://tex.z-dn.net/?f=%3D%20%282%29%282.20%5Ctimes10%5E6%20N%29cos19%C2%B0%20%280.720%5Ctimes10%5E3%20m%29)
![=2.99\times10^9J](https://tex.z-dn.net/?f=%3D2.99%5Ctimes10%5E9J)
d.88 n
Explanation:
The force exerted by gravity on the mass is 88N;
Gravitational force is usually experienced by two bodies with masses.
This force causes all objects on earth to accelerate at 9.8m/s².
Force of gravity = mass x acceleration due to gravity
In this case, the force exerted on the object by gravity will be the weight of the object.
Weight is a force applied gravity on a body:
Weight of the masses = Force of gravity = mass x acceleration
Given mass = 9kg
Force of gravity = 9 x 9.8 = 88.2N approximately 88N
learn more:
Weight and mass brainly.com/question/5956881
#learnwithBrainly