For rotational equilibrium of the door we can say that torque due to weight of the door must be counter balanced by the torque of external force
![F\times L = mg \times \frac{L}{2}](https://tex.z-dn.net/?f=F%5Ctimes%20L%20%3D%20mg%20%5Ctimes%20%5Cfrac%7BL%7D%7B2%7D)
here weight will act at mid point of door so its distance is half of the total distance where force is applied
here we know that
![mg = 145 N](https://tex.z-dn.net/?f=mg%20%3D%20145%20N)
now we will have
![F = \frac{mg}{2}](https://tex.z-dn.net/?f=F%20%3D%20%5Cfrac%7Bmg%7D%7B2%7D)
![F = \frac{145}{2} = 72.5 N](https://tex.z-dn.net/?f=F%20%3D%20%5Cfrac%7B145%7D%7B2%7D%20%3D%2072.5%20N)
so our applied force is 72.5 N
Answer:
The momentum of the photon is 1.707 x 10⁻²² kg.m/s
Explanation:
Given;
kinetic of electron, K.E = 100 keV = 100,000 eV = 100,000 x 1.6 x 10⁻¹⁹ J = 1.6 x 10⁻¹⁴ J
Kinetic energy is given as;
K.E = ¹/₂mv²
where;
v is speed of the electron
![K.E = \frac{1}{2}mv^2\\\\mv^2 = 2K.E \\\\v^2 = \frac{2K.E}{m} \\\\v = \sqrt{\frac{2K.E}{m}} \\\\but \ momentum ,P = mv\\\\(v)m = (\sqrt{\frac{2K.E}{m}})m\\\\P_{photon} = (\sqrt{\frac{2K.E}{m_e}})m_e\\\\P_{photon} = (\sqrt{\frac{2\times 1.6\times 10^{-14}}{9.11\times10^{-31}}})(9.11\times 10^{-31})\\\\P_{photon} = 1.707 \times 10^{-22} \ kg.m/s](https://tex.z-dn.net/?f=K.E%20%3D%20%5Cfrac%7B1%7D%7B2%7Dmv%5E2%5C%5C%5C%5Cmv%5E2%20%3D%202K.E%20%5C%5C%5C%5Cv%5E2%20%3D%20%5Cfrac%7B2K.E%7D%7Bm%7D%20%5C%5C%5C%5Cv%20%3D%20%5Csqrt%7B%5Cfrac%7B2K.E%7D%7Bm%7D%7D%20%5C%5C%5C%5Cbut%20%5C%20momentum%20%2CP%20%3D%20mv%5C%5C%5C%5C%28v%29m%20%3D%20%28%5Csqrt%7B%5Cfrac%7B2K.E%7D%7Bm%7D%7D%29m%5C%5C%5C%5CP_%7Bphoton%7D%20%3D%20%20%28%5Csqrt%7B%5Cfrac%7B2K.E%7D%7Bm_e%7D%7D%29m_e%5C%5C%5C%5CP_%7Bphoton%7D%20%3D%20%20%28%5Csqrt%7B%5Cfrac%7B2%5Ctimes%201.6%5Ctimes%2010%5E%7B-14%7D%7D%7B9.11%5Ctimes10%5E%7B-31%7D%7D%7D%29%289.11%5Ctimes%2010%5E%7B-31%7D%29%5C%5C%5C%5CP_%7Bphoton%7D%20%3D%201.707%20%5Ctimes%2010%5E%7B-22%7D%20%5C%20kg.m%2Fs)
Therefore, the momentum of the photon is 1.707 x 10⁻²² kg.m/s
Answer:
800 N
Explanation:
By Newton's third law which states that for every action, there is an equal and opposite reaction.
So, as the earth attracts the person towards its center, the person attracts the earth towards itself with the same magnitude of force but in the opposite direction.
Since the person is attracted towards the center of the earth by an 800 N gravitational force, the the earth is attracted toward the person with an 800 N reaction force.
Fibrous joint functions as a suture to tightly bind bones together so they do not move.
Acceleration = (change in speed) / (time for the change)
change in speed = (speed at the end) - (speed at the beginning)
change in speed = (37 km/hr) - (89 km/hr) = -52 km/hr
Acceleration = (-52 km/hr) / (6 sec)
Acceleration = (-26/3) km/(hr·sec)
Units: (1/hr·sec) · (hr/3600 sec) = 1 / 3600 sec²
(-26/3) km/(hr·sec) = (-26/3) km/(3600 sec²)
= -26,000/(3 · 3600) m/s²
<em>Acceleration = -2.41 m/s²</em>