Question

Calculate the velocity of a train that is headed south and has a mass of 4500 kilograms and whose momentum is 879,000 kg•m/sec

Answer 1

195 m/s south

Step-by-step explanation:

Momentum = mass × velocity

879000 kg m/s = (4500 kg) v

v = 195.33 m/s

Rounding, the velocity is approximately 195 m/s south.

Answer 2

`\large \boxed{\text{195 m$\cdot$ s}^(-1)\text{ south}}`

Step-by-step explanation:

The equation for momentum is

`\vec{p} = m\vec{v}`

Since momentum is a vector, we must specify both speed and direction.

Data:

p = 879 000 kg·m·s⁻¹ south

m = 4500 kg

Calculation:

`\begin{array}{rcl}\text{879 000 kg$\cdot$ m$\cdot$ s}^(-1) & = & \text{4500 kg} * v\\v & = & \frac{\text{879 000 kg $\cdot$ m$\cdot$ s}^(-1)}{\text{4500 kg}}\\\\& = & \textbf{195 m$\cdot$ s}^{\mathbf{-1}}\\\end{array}\\\text{The velocity of the train is $\large \boxed{\textbf{195 m$\cdot$ s}^{\mathbf{-1}}\textbf{ south}}$}`