Explanation:
When there is no change in chemical composition of a substance then it is known as physical change.
When we say that mass is conserved during a physical change then it means that total mass of the substance or object will remain the same from beginning till the end.
For example, a metal box of mass 20 grams is beaten with hammer. Its shape will change which is a physical change and after beaten with the hammer its mass still remains 20 grams.
Answer:
42.99°
Explanation:
= Kinetic friction force
= Pulling force at angle ![\theta](https://tex.z-dn.net/?f=%5Ctheta)
= Weight of the box = 150 N
Kinetic friction force
![F_h=\muN_h](https://tex.z-dn.net/?f=F_h%3D%5CmuN_h)
Pulling force at angle ![\theta](https://tex.z-dn.net/?f=%5Ctheta)
![F_{\theta}=\muN_{\theta}](https://tex.z-dn.net/?f=F_%7B%5Ctheta%7D%3D%5CmuN_%7B%5Ctheta%7D)
N = Pulling force
According to question
![\frac{F_h}{F_{\theta}}=\frac{2}{1}\\\Rightarrow \frac{\muN_h}{\muN_{\theta}}=2\\\Rightarrow \frac{N_h}{N_{\theta}}=2\\\Rightarrow N_{\theta}=\frac{N_h}{2}\\\Rightarrow N_{\theta}=\frac{150}{2}\\\Rightarrow N_{\theta}=75\ N](https://tex.z-dn.net/?f=%5Cfrac%7BF_h%7D%7BF_%7B%5Ctheta%7D%7D%3D%5Cfrac%7B2%7D%7B1%7D%5C%5C%5CRightarrow%20%5Cfrac%7B%5CmuN_h%7D%7B%5CmuN_%7B%5Ctheta%7D%7D%3D2%5C%5C%5CRightarrow%20%5Cfrac%7BN_h%7D%7BN_%7B%5Ctheta%7D%7D%3D2%5C%5C%5CRightarrow%20N_%7B%5Ctheta%7D%3D%5Cfrac%7BN_h%7D%7B2%7D%5C%5C%5CRightarrow%20N_%7B%5Ctheta%7D%3D%5Cfrac%7B150%7D%7B2%7D%5C%5C%5CRightarrow%20N_%7B%5Ctheta%7D%3D75%5C%20N)
Applying Newton's second law in the vertical direction we get
![N_h-Nsin\theta=N_{\theta}\\\Rightarrow 150-110sin\theta=75\\\Rightarrow \theta=sin^{-1}\frac{75}{110}\\\Rightarrow \theta=42.99\ ^{\circ}](https://tex.z-dn.net/?f=N_h-Nsin%5Ctheta%3DN_%7B%5Ctheta%7D%5C%5C%5CRightarrow%20150-110sin%5Ctheta%3D75%5C%5C%5CRightarrow%20%5Ctheta%3Dsin%5E%7B-1%7D%5Cfrac%7B75%7D%7B110%7D%5C%5C%5CRightarrow%20%5Ctheta%3D42.99%5C%20%5E%7B%5Ccirc%7D)
The angle is 42.99°
1 G = 9.8 m/s²
2 G = 19.6 m/s²
.
.
5 G = 49 m/s²
The frequency of sodium light in vacuum is 5 ×
Hz.
Answer:
Option e
Explanation:
It is known that frequency of a wave is inversely proportional to the wavelength of the wave. And the proportionality constant is the speed of light in vacuum. As the speed of light in vacuum is known as 3×
m/s and the wavelength of the light in vacuum is given as 6 ×
m, then the frequency of the light is determined as
Frequency = Speed of light in vacuum/Wavelength of light
Frequency = ![\frac{3*10^{8} }{6*10^{-7} }](https://tex.z-dn.net/?f=%5Cfrac%7B3%2A10%5E%7B8%7D%20%7D%7B6%2A10%5E%7B-7%7D%20%7D)
Frequency = 0.5×
= 5 ×
Hz.
So the frequency of sodium light in vacuum is 5 ×
Hz.
Answer:
South
Explanation:
cause frictional fore always acts opposite to the direction of motion and opposite of North