Question

What is the momentum in Kg m/s of a 10 kg truck travelling at A) 5 m/s B) 20 cm/s C) 36 km/h?​

Answer 1

A) 50 kg m/s

B) 2 kg m/s

C) 100 kg m/s

Step-by-step explanation:

Recall that momentum is a physical quantity defined by the product of the object's mass times its velocity. Therefore, in our case the truck's momentum (p) is:

A) p = m * v = 10 kg * 5 m/s = 50 kg m/s

B) p = m * v = 10 kg * 0.20 m/s = 2 kg m/s (notice that the velocity in cm/s was converted into m/s before multiplying)

C) the conversion from km/h to m/s is a little more involved, so we taclke it first:

since 1 km = 1000 m and 1 hour = 3600 seconds, we convert 36 km/h by replacing each unit by its m and s expression as shown below:

`36 (km)/(h) =36\,(1000\,m)/(3600\,\,s)=10\,(m)/(s)`

Then, the momentum is: p = m * v = 10 kg * 10 m/s = 100 kg m/s