Answer:
The sum of momenta of each object before and after collision is equal . Thus when they collide , their momentum will change but its sum will be sane as the sum of the momentum before collision
D. it is thickest in the middle
Mechanical advantage = ideal mechanical advantage x efficiency = 3.5 x 0.6 = 2.1
The mechanical advantage of the inclined plane is 2.1
Answer:
1) f= 8.6 GHz
2) t= 0.2 ms
Explanation:
1)
- Since microwaves are electromagnetic waves, they move at the same speed as the light in vacuum, i.e. 3*10⁸ m/s.
- There exists a fixed relationship between the frequency (f) , the wavelength (λ) and the propagation speed in any wave, as follows:
![v = \lambda * f (1)](https://tex.z-dn.net/?f=v%20%3D%20%5Clambda%20%2A%20f%20%281%29)
- Replacing by the givens, and solving for f, we get:
![f =\frac{c}{\lambda} =\frac{3e8m/s}{0.035m} = 8.57e9 Hz (2)](https://tex.z-dn.net/?f=f%20%3D%5Cfrac%7Bc%7D%7B%5Clambda%7D%20%3D%5Cfrac%7B3e8m%2Fs%7D%7B0.035m%7D%20%3D%208.57e9%20Hz%20%282%29)
⇒ f = 8.6 Ghz (with two significative figures)
2)
- Assuming that the microwaves travel at a constant speed in a straight line (behaving like rays) , we can apply the definition of average velocity, as follows:
where v= c= speed of light in vacuum = 3*10⁸ m/s
d= distance between mountaintops = 52 km = 52*10³ m
![t = \frac{d}{c} = \frac{52e3m}{3e8m/s} = 17.3e-5 sec = 0.173e-3 sec = 0.173 ms (4)](https://tex.z-dn.net/?f=t%20%3D%20%5Cfrac%7Bd%7D%7Bc%7D%20%3D%20%5Cfrac%7B52e3m%7D%7B3e8m%2Fs%7D%20%3D%2017.3e-5%20sec%20%3D%200.173e-3%20sec%20%3D%200.173%20ms%20%284%29)
⇒ t = 0.2 ms (with two significative figures)
Answer:21.18 m
Explanation:
Given
initial speed u=10 m/s
height of building h=22 m
time taken to complete 22 m
![h=ut+\frac{1}{2}at^2](https://tex.z-dn.net/?f=h%3Dut%2B%5Cfrac%7B1%7D%7B2%7Dat%5E2)
initial vertical velocity =0
![22=\frac{1}{2}gt^2](https://tex.z-dn.net/?f=22%3D%5Cfrac%7B1%7D%7B2%7Dgt%5E2)
![t=\sqrt{\frac{22\times 2}{g}}](https://tex.z-dn.net/?f=t%3D%5Csqrt%7B%5Cfrac%7B22%5Ctimes%202%7D%7Bg%7D%7D)
![t=2.11 s](https://tex.z-dn.net/?f=t%3D2.11%20s)
Horizontal Distance moved
![R=u_x\times t](https://tex.z-dn.net/?f=R%3Du_x%5Ctimes%20t)
![R=10\times 2.11](https://tex.z-dn.net/?f=R%3D10%5Ctimes%202.11)
![R=21.18 m](https://tex.z-dn.net/?f=R%3D21.18%20m)