The following time dependent force is applied to a 2 kg block that is initially at rest on a frictionless and horizontal surface. F open parentheses t close parentheses equals open parentheses 4 straight N over straight s close parentheses t What is the displacement (in m) of the block after 3 s?

Respuesta :

Answer:

The displacement of the block is 9 m.

Explanation:

Given that,

Mass of block = 2 kg

Time = 3 sec

The force is

[tex]F(t)=4t[/tex]

The acceleration is

[tex]a=\dfrac{F}{m}[/tex]

Put the value into the formula

[tex]a=\dfrac{4t}{2}[/tex]

[tex]a=2t[/tex]

We need to calculate the velocity

Using formula of acceleration

[tex]v=\int_{0}^{t}{a dt}[/tex]

Put the value into the formula

[tex]v=\int_{0}^{3}(2t dt)[/tex]

[tex]v=(\dfrac{2t^2}{2})_{0}^{3}[/tex]

[tex]v=(t^2)_{0}^{3}[/tex]

[tex]v=9\ m/s[/tex]

We need to calculate the displacement

Using formula of velocity

[tex]s=\int_{0}^{3}(v dt)[/tex]

[tex]s=(t^2)_{0}^{3}[/tex]

[tex]s=(\dfrac{t^3}{3})_{0}^{3}[/tex]

[tex]s=9\ m/s[/tex]

Hence, The displacement of the block is 9 m.

Answer:

[tex]s=9\ m[/tex]

Explanation:

Given:

mass of the block,[tex]m=2\ kg[/tex]

force as a function of time, [tex]F(t)=4t[/tex]

time of observation, [tex]t=3\ s[/tex]

initial velocity of the block, [tex]u=0\ m.s^{-1}[/tex]

Now the acceleration:

[tex]a=\frac{F}{m}[/tex]

[tex]a=\frac{4t}{2}[/tex]

[tex]a=2t[/tex]

Now the related velocity:

[tex]v=\int {a} \, dt[/tex]

[tex]v=\int 2t\ dt[/tex]

[tex]v=t^2[/tex]

Integrating again we get the displacement:

[tex]s=\int\limits^3_0 v\ dt[/tex]

[tex]s=\int\limits^3_0 t^2\ dt[/tex]

[tex]s=\frac{t^3}{3}\vert^3_0[/tex]

[tex]s=9\ m[/tex]