Answer:
50 N.
Explanation:
On top of a horizontal surface, the normal force acting on an object is equivalent to the force of gravity acting on the object. That is:
![\displaystyle \begin{aligned} F_N = F_g & = ma \\ & = mg\end{aligned}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Cbegin%7Baligned%7D%20F_N%20%3D%20F_g%20%26%20%3D%20ma%20%5C%5C%20%26%20%3D%20mg%5Cend%7Baligned%7D)
The mass of the block is 5 kg and the given force due to gravity is 10 N/kg. Substitute and evaluate:
![\displaystyle F_N = F_g = (5\text{ kg})(10 \text{ N/kg}) = 50 \text{ N}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20F_N%20%3D%20F_g%20%3D%20%285%5Ctext%7B%20kg%7D%29%2810%20%5Ctext%7B%20N%2Fkg%7D%29%20%3D%2050%20%5Ctext%7B%20N%7D)
In conclusion, the normal force acting on the block is 50 N.
The potential energy of the box when it gets to the top is
(mass) (gravity) (height)
= (7 kg) (9.8 m/s²) (5 m)
= 343 joules.
That's the work done against the force of gravity. Any
additional work is done against the force of friction.
Answer:
A ratio of equivalent units
Explanation:
A conversion factor is a ratio of equivalent units and depends on which units are to be converted.
For example we want to convert 275 [mm] to inches, so we have to find the right conversion factor to allow us to work that conversion.
275 [mm] = inches = ?
![275 [mm] * \frac{1in}{25.4mm} = 10.82 [in]](https://tex.z-dn.net/?f=275%20%5Bmm%5D%20%2A%20%5Cfrac%7B1in%7D%7B25.4mm%7D%20%3D%2010.82%20%5Bin%5D)
In this case the ratio is 1/25.4 = 0.039 [in/mm]