Question

What is the momentum of a $100000Kg$ truck whose velocity is $2{\text{ m/s?}}$
(A) $2 \times {10^5}{\text{ Kg m/s}}$
(B) $1 \times {10^5}{\text{ Kg m/s}}$
(C) $4{\text{ Kg m/s}}$
(D) None of these

Answer 1

Hint
In the question they have provided the value of the mass of the truck and velocity of the truck. Use the momentum formula to find the momentum of the truck. If the standard units are not provided then change it into standard units.
$\Rightarrow {\text{Momentum = mass}} \times {\text{velocity}}$
$\Rightarrow P{\text{ = m}} \times {\text{v}}$
Where, ${\text{p is the momentum}}$, ${\text{m is the mass}}$, ${\text{v is the velocity}}$.

Complete step by step answer
Given, The mass of the truck is $100000Kg$,
The velocity of the truck is $2{\text{ m/s}}$.
Momentum: The momentum of an object is defined as the product of mass and velocity of the object. Momentum is a vector quantity. It is represented by $'P'$ and the unit of momentum is $Kg{\text{ }}m{s^{ - 1}}$.
There are two types of momentum, linear momentum and angular momentum. When an object in linear motion moves with a velocity it is called linear momentum. When an object moves in angular motion with an angular velocity then it is called angular momentum.
Velocity: The velocity of an object is defined as the change of rate of its position with respect to time. The unit of velocity is ${\text{m/s}}{\text{.}}$ Velocity is a vector quantity.
Now, substitute the given value in the momentum formula.
${\text{Momentum = mass}} \times {\text{velocity}}$
$\Rightarrow P{\text{ = m}} \times {\text{v}}$
$\Rightarrow 100000 \times 2$
$\Rightarrow 200000{\text{ Kg m/s}}$
$\Rightarrow 2 \times {10^5}{\text{ Kg m/s}}$
Hence the correct answer is option (A) $2 \times {10^5}{\text{ Kg m/s}}$

Note
There is an interesting fact about momentum, certain objects such as planets, stars, natural satellites in space have momentum in space that allow them to continue to revolve around for example the earth and other planets revolve around the sun continuously at a constant rate. There is no air or gravity in space. It is a vacuum which is one of the reasons for that, but on earth there is air and gravity and other factors that slow down and stop the momentum of the object.