As the box is moving with a constant velocity, the two forces acting on the box are canceling each other.
Then friction force = 80 Newtons but in the opposite direction.
Friction force = Mu * Normal force exerted by ground = Mu * weight of box
So we find Mu.
Mu = coefficient of friction between box and horizontal surface
= Force of friction / weight = 80 / 50 * 9.81 = 0.163
When an identical box is placed on top, the force of friction is
= Mu * total weight = 0.163 * (50+50) * 9.81 = 159.9 Newtons
Answer: T is greater
Explanation:
Since the elevator is moving against gravity more work will be done on the rope
T= m(g+a)
Answer:
0.000234 seconds
Explanation:
Since the row is 0.15m, its radius of rotation must be 0.15 / 2 = 0.075 m
We can start by calculating the angular speed of the rod:
Since one revolution equals to 2π rad. The speed in revolution per second must be
26800 / 2π = 4265 revolution/s
The number of seconds per revolution, or period, is the inverse:
1/4265 = 0.000234 seconds
Answer:
a)
, b) ![\vec F_{B} = -8.766\times 10^{-14}\,T\,k](https://tex.z-dn.net/?f=%5Cvec%20F_%7BB%7D%20%3D%20-8.766%5Ctimes%2010%5E%7B-14%7D%5C%2CT%5C%2Ck)
Explanation:
a) The magnetic force experimented by a particle has the following vectorial form:
![\vec F_{B} = q\cdot \vec v \times \vec B](https://tex.z-dn.net/?f=%5Cvec%20F_%7BB%7D%20%3D%20q%5Ccdot%20%5Cvec%20v%20%5Ctimes%20%5Cvec%20B)
The charge of the electron is equal to
. Then, cross product can be solved by using determinants:
![\vec F_{B} = \begin{vmatrix}i&j&k\\-4.165\times 10^{-13}\, C\cdot \frac{m}{s} &-5.126\times 10^{-13}\,C\cdot \frac{m}{s} &0\,C\cdot \frac{m}{s} \\0.041\,T&-0.16\,T&0\,T\end{vmatrix}](https://tex.z-dn.net/?f=%5Cvec%20F_%7BB%7D%20%3D%20%5Cbegin%7Bvmatrix%7Di%26j%26k%5C%5C-4.165%5Ctimes%2010%5E%7B-13%7D%5C%2C%20C%5Ccdot%20%5Cfrac%7Bm%7D%7Bs%7D%20%26-5.126%5Ctimes%2010%5E%7B-13%7D%5C%2CC%5Ccdot%20%5Cfrac%7Bm%7D%7Bs%7D%20%260%5C%2CC%5Ccdot%20%5Cfrac%7Bm%7D%7Bs%7D%20%5C%5C0.041%5C%2CT%26-0.16%5C%2CT%260%5C%2CT%5Cend%7Bvmatrix%7D)
The magnetic force is:
![\vec F_{B} = 8.766\times 10^{-14}\,T\,k](https://tex.z-dn.net/?f=%5Cvec%20F_%7BB%7D%20%3D%208.766%5Ctimes%2010%5E%7B-14%7D%5C%2CT%5C%2Ck)
b) The charge of the proton is equal to
. Then, cross product has the following determinant:
![\vec F_{B} = \begin{vmatrix}i&j&k\\4.165\times 10^{-13}\, C\cdot \frac{m}{s} &5.126\times 10^{-13}\,C\cdot \frac{m}{s} &0\,C\cdot \frac{m}{s} \\0.041\,T&-0.16\,T&0\,T\end{vmatrix}](https://tex.z-dn.net/?f=%5Cvec%20F_%7BB%7D%20%3D%20%5Cbegin%7Bvmatrix%7Di%26j%26k%5C%5C4.165%5Ctimes%2010%5E%7B-13%7D%5C%2C%20C%5Ccdot%20%5Cfrac%7Bm%7D%7Bs%7D%20%265.126%5Ctimes%2010%5E%7B-13%7D%5C%2CC%5Ccdot%20%5Cfrac%7Bm%7D%7Bs%7D%20%260%5C%2CC%5Ccdot%20%5Cfrac%7Bm%7D%7Bs%7D%20%5C%5C0.041%5C%2CT%26-0.16%5C%2CT%260%5C%2CT%5Cend%7Bvmatrix%7D)
The magnetic force is:
![\vec F_{B} = -8.766\times 10^{-14}\,T\,k](https://tex.z-dn.net/?f=%5Cvec%20F_%7BB%7D%20%3D%20-8.766%5Ctimes%2010%5E%7B-14%7D%5C%2CT%5C%2Ck)
They can change because the law of conservation of energy allows it to happen, for example when you are sitting, your body is at a potential energy state, meaning you are inert, you are not moving, but when you get up and suddenly start walking or running, that energy is converted to kinetic energy, meaning that you are moving and can be changed back into potential energy if all of a sudden you stop running or walking to rest or sit down. This is just an example of how energy can are transferred multiple ways