Answer:
a) 37.8 W
b) 2 Nm
Explanation:
180 g = 0.18 kg
We can also convert 180 revolution per minute to standard angular velocity unit knowing that each revolution is 2π and 1 minute equals to 60 seconds
180 rpm = 180*2π/60 = 18.85 rad/s
We can use the heat specific equation to find the rate of heat exchange of the steel drill and block:
![\dot{E} = mc\Delta \dot{t} = 0.18*420*0.5 = 37.8 J/s](https://tex.z-dn.net/?f=%5Cdot%7BE%7D%20%3D%20mc%5CDelta%20%5Cdot%7Bt%7D%20%3D%200.18%2A420%2A0.5%20%3D%2037.8%20J%2Fs)
Since the entire mechanical work is used up in producing heat, we can conclude that the rate of work is also 37.8 J/s, or 37.8 W
The torque T required to drill can be calculated using the work equation
![E = T\theta](https://tex.z-dn.net/?f=E%20%3D%20T%5Ctheta)
![\dot{E} = T\dot{\theta} = T\omega](https://tex.z-dn.net/?f=%5Cdot%7BE%7D%20%3D%20T%5Cdot%7B%5Ctheta%7D%20%3D%20T%5Comega)
![T = \frac{\dot{E}}{\omega} = \frac{37.8}{18.85} = 2 Nm](https://tex.z-dn.net/?f=T%20%3D%20%5Cfrac%7B%5Cdot%7BE%7D%7D%7B%5Comega%7D%20%3D%20%5Cfrac%7B37.8%7D%7B18.85%7D%20%3D%202%20Nm)
Q. The energy emitted from the sun is a product of ________.
A. Fusion
Answer:
![emf= 9.88 \times 10^{-3} T](https://tex.z-dn.net/?f=emf%3D%209.88%20%5Ctimes%2010%5E%7B-3%7D%20T)
Explanation:
Given:
- Length of the beam,
![l=13\,m](https://tex.z-dn.net/?f=l%3D13%5C%2Cm)
- speed of the beam,
![v=20\,m.s^{-1}](https://tex.z-dn.net/?f=v%3D20%5C%2Cm.s%5E%7B-1%7D)
- magnitude of the vertical magnetic field,
![B=38\times 10^{-6} T](https://tex.z-dn.net/?f=B%3D38%5Ctimes%2010%5E%7B-6%7D%20T)
According to the Faraday's law the emf induced in a rod passing transversely through a magnetic field is given as:
![emf= l.v.B](https://tex.z-dn.net/?f=emf%3D%20l.v.B)
![emf=13\times 20\times 38\times 10^{-6}](https://tex.z-dn.net/?f=emf%3D13%5Ctimes%2020%5Ctimes%2038%5Ctimes%2010%5E%7B-6%7D)
![emf= 9.88 \times 10^{-3} T](https://tex.z-dn.net/?f=emf%3D%209.88%20%5Ctimes%2010%5E%7B-3%7D%20T)
The correct option is PLUM PUDDING, SOLAR SYSTEM, ELECTRON CLOUD.
J. J Thompson was the scientist who proposed the plum pudding theory of atomic model. Neil Borh was the one who developed the solar system model of atomic theory while the electron cloud model of atomic theory that is presently been used was developed by an Australian scientist called Erwin Schrodinger.<span />
Answer:
400 kilogram
Explanation:
Force exerted is directly proportional to the mass of an object.
F=ma where m is mass and a is acceleration. Taking uniform acceleration on all objects then the larger the mass the higher the force and vice versa. Theredore, among the masses given, 400 kilograms is the largest hence it exerts the largest force at the bottom