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If a 20 N force acts on a 10 kg object for 0.5 seconds. If the object starts at rest, what would it’s new p (momentum) and v (velocity) be?

Respuesta :

Answer:

[tex]p=10\:\text{kgm/s}},\\v_f=1\:\text{m/s}[/tex]

Explanation:

From Newton's 2nd Law, we have [tex]\Sigma F=ma[/tex]. We can use this to find the acceleration of object after 20 N (force) is applied to the 10 kg object.

Substituting given values, we have:

[tex]\Sigma F=ma, \\20=10a,\\a=\frac{20}{10}=2\:\mathrm{m/s^2}[/tex]

Now that we have acceleration, we can find the final velocity of object (after 0.5 seconds) using the following kinematics equation:

[tex]v_f=v_i+at[/tex], where [tex]v_f[/tex] is final velocity, [tex]v_i[/tex] is initial velocity, [tex]a[/tex] is acceleration, and [tex]t[/tex] is time.

Solving for final velocity:

[tex]v_f=0+2\cdot 0.5,\\v_f=\boxed{1\:\text{m/s}}[/tex]

The momentum of an object is given as [tex]p=mv[/tex]. Since we've found the final velocity and mass stays constant, we have:

[tex]p=10\cdot 1=\boxed{10\:\text{kgm/s}}[/tex]