Conversion of the Unit of Speed, Density and Pressure
- When doing the conversion of unit such as speed and density, we are advised to write the quantity in the fraction form.
- For example, to convert 5km/h to m/s, we write 5km/h as
![](http://spmphysics.blog.onlinetuition.com.my/wp-content/uploads/sites/4/2020/02/formula15.svg)
- After that, we convert the km to m and h (hour) to s (second)
![](http://spmphysics.blog.onlinetuition.com.my/wp-content/uploads/sites/4/2020/02/formula16a.svg)
Example
Complete the following unit conversion of speed.
- 90 kmh-1 = __________ ms-1
- 8.12 ms-1 = __________ kmh-1
Answer:![](http://spmphysics.blog.onlinetuition.com.my/wp-content/uploads/sites/4/2020/02/formula17.svg)
Example
Complete the following unit conversion of density and pressure.
- 760 kgm-3 = __________ gcm-3
- 5.1 gcm-3 = __________ kgm-3
- 3600 Nm-2 = __________ Ncm-2
- 3.16×10-5 Ncm-2= __________ Nm-2
Answer:
a.
![](http://spmphysics.blog.onlinetuition.com.my/wp-content/uploads/sites/4/2020/02/formula18.svg)
b.
![](http://spmphysics.blog.onlinetuition.com.my/wp-content/uploads/sites/4/2020/02/formula19.svg)
c.
![](http://spmphysics.blog.onlinetuition.com.my/wp-content/uploads/sites/4/2020/02/formula20.svg)
d.
![](http://spmphysics.blog.onlinetuition.com.my/wp-content/uploads/sites/4/2020/02/formula21.svg)