Question

expression for external force
in the term of momentum​

Answer 1

Answer:

In symbols, linear momentum p is defined to be p = mv, where m is the mass of the system and v is its velocity. The SI unit for momentum is kg · m/s. Newton's second law of motion in terms of momentum states that the net external force equals the change in momentum of a system divided by the time over which it changes.

Answer 2

Answer:

$\maltese\underline{\textsf{\textbf{AnsWer :}}}\:\maltese✠$

Let initial momentum ($p_i$) be mu

Let final momentum ($p_f$) be mv

According to 2nd law of motion

$\frac{p_f - p_i}{t} \propto \: f$

$\implies \: f \propto \frac{mv \: - mu}{t}$

$\implies \: f \propto \frac{m(v - u)}{t}$

$f \propto \: ma \: \: \: \: \: \: ( \frac{v - u}{t } = a )$

To remove the proportionality sign. We would add k as the proportionality constant

$f = kma \\ f = ma \:$

because by the definition of force k = 1

$\footnotesize \longrightarrow\: \underline{ \boxed{\sf Force \:= \: mass \times \: acceleration}}$

Explanation: