Answer:
A. 243 N
Explanation:
Friction is the force that opposes the relative motion between systems that are in contact.
This friction force that opposes the motion of the oak chest across the oak surface will be equal and opposite to that exerted by the woman.
First find the normal force which is the force that would point directly upwards to support weight of the block.
Normal force, N= mg where m is the mass of the chest and g is the acceleration due to gravity.
Given m=40 kg and g=9.80 m/s²
N force=40×9.80 =392N
Then find the force of friction which is given by the formula;
<em>F=μN where μ is friction coefficient for the oak chest and N is the normal force on the chest</em>
Given <em>μ</em>=0.620 and N force = 392 N then it will be;
F=0.620× 392 =243.04 N
Answer : 243 N
Answer:
Latin
Explanation:
In order for the scientists to have a common and official name for a particular thing that can be understood by every scientist in the world, a single language has been established for the purpose. The language chosen is the Latin language. The official scientific names are given in this language, so it is a necessity for the scientists to know and understand this language. The terms that are commonly used are regional, and they come in many different languages, which is why this language has been chosen. Occasionally, the ancient Greek language is used as well, though much less than the Latin.
No, that's silly.
You've got your Pfund series where electrons fall down to the 5th level,
your Brackett series where they fall to the 4th level, and your Paschen
series where they fall to the 3rd level. All of those transitions ploop out
photons at Infrared wavelengths.
THEN next you get your Balmer series, where the electrons fall in
to the 2nd level. Most of those are at visible wavelengths, but even
a few of the Balmer transitions are in the Ultraviolet.
And then there's the Lyman series, where electrons fall all the way
down to the #1 level. Those are ALL in the ultraviolet.
Given : A ball of mass 40 g moving at a velocity of 4 m/s.
To find : Calculate the kinetic energy in joules ?
Solution :
The kinetic energy formula is given by,
where, v is the velocity v=4 m/s
m is the mass m=40 g
Convert g into kg,
Substitute the values,
Therefore, the kinetic energy is 0.32 Joules.
Answer:
Explanation:
We shall apply law of refraction which is as follows
sin i / sinr = μ , where i is angle of incidence , r is angle of refraction and μ is refractive index
here i = θa = 22.5°
r = θb
μ = 1.77
sin22.5 / sinθb = 1.77
.3826 / sinθb = 1.77
sinθb = .216
θb = 12.5 °.
