Answer:
C
Explanation:
- Let acceleration due to gravity @ massive planet be a = 30 m/s^2
- Let acceleration due to gravity @ earth be g = 30 m/s^2
Solution:
- The average time taken for the ball to cover a distance h from chin to ground with acceleration a on massive planet is:
t = v / a
t = v / 30
- The average time taken for the ball to cover a distance h from chin to ground with acceleration g on earth is:
t = v / g
t = v / 9.81
- Hence, we can see the average time taken by the ball on massive planet is less than that on earth to reach back to its initial position. Hence, option C
Answer:
A: The acceleration is 7.7 m/s up the inclined plane.
B: It will take the block 0.36 seconds to move 0.5 meters up along the inclined plane
Explanation:
Let us work with variables and set
![m=5kg\\\\F_H=100N\\\\\mu=0.3\\\\\theta=37^o.](https://tex.z-dn.net/?f=m%3D5kg%5C%5C%5C%5CF_H%3D100N%5C%5C%5C%5C%5Cmu%3D0.3%5C%5C%5C%5C%5Ctheta%3D37%5Eo.)
As shown in the attached free body diagram, we choose our coordinates such that the x-axis is parallel to the inclined plane and the y-axis is perpendicular. We do this because it greatly simplifies our calculations.
Part A:
From the free body diagram we see that the total force along the x-axis is:
![F_{tot}=mg*sin(\theta)+F_s-F_Hcos(\theta).](https://tex.z-dn.net/?f=F_%7Btot%7D%3Dmg%2Asin%28%5Ctheta%29%2BF_s-F_Hcos%28%5Ctheta%29.)
Now the force of friction is
where
is the normal force and from the diagram it is ![F_y=mg*cos(\theta).](https://tex.z-dn.net/?f=F_y%3Dmg%2Acos%28%5Ctheta%29.)
Thus
Therefore,
![F_{tot}=mg*sin(\theta)+\mu*mg*cos(\theta)-F_Hcos(\theta)\\\\=mg(sin(\theta)+\mu*cos(\theta))-F_Hcos(\theta).](https://tex.z-dn.net/?f=F_%7Btot%7D%3Dmg%2Asin%28%5Ctheta%29%2B%5Cmu%2Amg%2Acos%28%5Ctheta%29-F_Hcos%28%5Ctheta%29%5C%5C%5C%5C%3Dmg%28sin%28%5Ctheta%29%2B%5Cmu%2Acos%28%5Ctheta%29%29-F_Hcos%28%5Ctheta%29.)
Substituting the value for
we get:
![F_{tot}= -38.63N.](https://tex.z-dn.net/?f=F_%7Btot%7D%3D%20-38.63N.)
Now acceleration is simply
![a=\frac{F_H}{m} =\frac{-38.63N}{5kg} =-7.7m/s.](https://tex.z-dn.net/?f=a%3D%5Cfrac%7BF_H%7D%7Bm%7D%20%3D%5Cfrac%7B-38.63N%7D%7B5kg%7D%20%3D-7.7m%2Fs.)
The negative sign indicates that the acceleration is directed up the incline.
Part B:
![d=\frac{1}{2} at^2](https://tex.z-dn.net/?f=d%3D%5Cfrac%7B1%7D%7B2%7D%20at%5E2)
Which can be rearranged to solve for t:
![t=\sqrt{\frac{2d}{a} }](https://tex.z-dn.net/?f=t%3D%5Csqrt%7B%5Cfrac%7B2d%7D%7Ba%7D%20%7D)
Substitute the value of
and
and we get:
which is our answer.
Notice that in using the formula to calculate time we used the positive value of
, because for this formula absolute value is needed.
Autosomes are homologous chromosomes i.e. chromosomes which contain the same genes (regions of DNA) in the same order along their chromosomal arms. The chromosomes of the 23rd pair are called allosomes consisting of two X chromosomes in most females, and an X chromosome and a Y chromosome in most males.
Answer:
The human body runs at a constant 37 ºC but the air around you at room temperature is about 20-25 ºC which means heat is constantly leaving your body to warm your surroundings and maintain thermal equilibrium. You don't lose much energy doing this however as air heats reasonably quickly
Explanation:
Answer:
a) I = 13.38 kg m / s, b) F = 1,373 10³ N
Explanation:
The impulse is given by the relation
I = ∫ F dt = Δp
I = p_f -p₀
I = m (v_f - v₀)
take the ball's exit direction as positive, whereby the ball velocities
v₀ = -90mph, the final velocity v_f = + 54 m / s
Let's reduce the units to
I = 0.142 [54- (-40.23) ]
the SI system
v₀ = - 90 mph (1609.34 m / 1 mile) (1h / 3600 s = -40.23 m / s
m = 142 g (1kg / 1000) = 0.142 kg
we calculate
I = 0.142 [54- (-40) ]
I = 13.38 kg m / s
b) let's use the definition of momentum
I = ∫ F .dt
I = F ∫ dt
F = I / t
F = 13.38 / 0.008
F = 1,373 10³ N