Question

(a) what is the mass of a large ship that has a momentum of 1.40 ✕ 109 kg · m/s, when the ship is moving at a speed of 46.0 km/h?

Answer 1

momentum = mass × velocity

We need to convert all our units to SI units, for our equation. This means momentum must be specified on kgm/s (which it conveniently is in the question), mass should be in kg and velocity should be in m/s (which it isnt so we need to convert it).

A quick hack to convert from km/h to m/s is to divide the value by 3.6 . To convert the otherway, simply multiply by 3.6 .

So

46.0/3.6 = 12.777777 m/s (recurring)

Now we can substitute these values into our equation. I will keep the speed as 46.0/3.6 for accuracy.

momentum = mass × velocity
1.40 × 109 = mass × 46.0/3.6
therefore mass =
$\frac{1.40 \times {10}^{9} }{ \frac{46.0}{3.6} }$

Answer 2

Answer: 1.1 × 10^8 m

Explanation: this is a nice question

Taking note of what is given

The momentum of the ship = 1.4 × 10^9 kg.m/s

The velocity of the sheep = 46 km/h

We need to convert the velocity to m/s

Using 1000/ (60×60)

   = 0.27778

The above value would be used to multiple the velocity given

    = 46 × 027778

    = 12.778m/s

Using the formula for

Momentum = mass × acceleration

    1.4 × 10^9   = m × 12.778

           = 1.1 × 10^8 m