A constant force of 5N acts for 5sec on a mass of 5kg initially at test. Calculate the final momentum

Answer 1

To calculate the final momentum of the mass after a force has acted on it, we can use the following steps:

1. Calculate the acceleration (a) using Newton's second law of motion: $$F=m\cdot a$$ where:

   • $F$ = force (5 N)
   • $m$ = mass (5 kg)

   Rearranging gives: $$a=\frac{F}{m}=\frac{5,\text{N}}{5,\text{kg}}=1,{\text{m/s}}^2$$

2. Calculate the change in velocity (∆v) using the formula: $$\mathrm{\Delta }v=a\cdot t$$ where:

   • $t$ = time (5 seconds)

   So: $$\mathrm{\Delta }v=1,{\text{m/s}}^2\cdot 5,\text{s}=5,\text{m/s}$$

3. Determine the final velocity (v) of the mass. Since it starts from rest (initial velocity $u=0$): $$v=u+\mathrm{\Delta }v=0+5,\text{m/s}=5,\text{m/s}$$

4. Calculate the final momentum (p) using the formula: $$p=m\cdot v$$ Substituting the mass and final velocity: $$p=5,\text{kg}\cdot 5,\text{m/s}=25,\text{kg m/s}$$

Thus, the final momentum of the mass is $\boxed{{\displaystyle 25,\text{kg m/s}}}$.