Question

What is the mass of a dog running at a speed of 5 m/s and a momentum of 120.5 kgm/s?

Answer 1

Given:

Momentum of the dog (p) = 120.5 kg m/s

Speed of the dog (v) = 5 m/s

To Find:

Mass of the dog (m)

Concept/Theory:

$\underline{\underline{ \bf{\Large{Momentum}}}}$

• It is defined as the quantity of motion contained in a body.
• It is measured as the product of mass of the body and it's speed.
• It is represented by p.
• It's SI unit is kg m/s
• Mathematical Representation/Equation of Momentum: $\boxed{ \bf{p = mv}}$

Answer:

By using equation of momentum, we get:

$\rm \longrightarrow m = \dfrac{p}{v} \\ \\ \rm \longrightarrow m = \dfrac{120.5}{5} \\ \\ \rm \longrightarrow m = 24.1 \: kg$

$\therefore$ Mass of the dog (m) = 24.1 kg