Answer:
Explanation:
The oly way we can figure this out is if the boy is pulling the sled at a constant velocity. If not, we need a value for acceleration, and you don't have that here. If the boy is pulling the sled at a constant velocity, then the value for acceleration is 0, making this a really simple problem. I'm going with that, since there is no way to answer you otherwise. If velocity is not constant, please either repost the question or put it in the notes section under the question as it stands. If acceleration is 0, then
F - f = ma becomes
F - f = m(0) which is
F - f = 0 and
F = f which says that the applied force is the same as the frictional force. We need then to find the frictional force, which has an equation of
f = μ
where normal force is the same as the weight of the 2 girls. We will find that, then:
Each girl's mass is different so the normal force/weight equation is
w = (30.0)(9.8) + (40.0)(9.8) to get
w = 290 + 390 and
w = 680. Plug that into the frictional force equation:
f = (.120)(680) so
f = 82N
Answer:
Atoms distance is reduced .
Explanation:
In liquids atoms locate themselves relatively at more distance as compared to solids. When energy is extracted out of liquids and atoms are left to come closer they arrange themselves at shorter distance and solidify .
what kind of question is this....anyways...
Yes, we are real and yes we do exist. Without God there would be no creation or any type of life on earth. So, yes because of God Himself the creator of us we exist.
Answer:
0.7 secs
Explanation:
In this question, the speed does not change as the mass changes. So we can use
Δ<em>t=Δ∨x/χgμ............................equ 1</em>
To stop, the final speed will be 0
Therefore,
<em>Δvx=vf-vt</em>
Δvx=0-4m/s
= -4m/s
Now substitute the various values in equ 1
Δ<em>t=Δ∨x/χgμ</em>
Δ<em>t= -</em>4m/s/(9.8m/s∧2) (0.6)
Δ<em>t=</em>0.7 secs
White objects do not absorb all wavelenghts. The statement is false