A student pushes a 21-kg box initially at rest, horizontally along a frictionless surface for 10.0 m and then releases the box to continue sliding. If the student pushes with a constant 10 N force, what is the box's speed when it is released?

Respuesta :

Answer:v=3.08 m/s

Explanation:

Given

mass of student [tex]m=21 kg[/tex]

distance moved [tex]d=10 m[/tex]

Force applied [tex]F=10 N[/tex]

acceleration of system during application of force is a

[tex]a=\frac{F}{m}=\frac{10}{21}=0.476 m/s^2[/tex]

using [tex]v^2-u^2=2 as[/tex]

where v=final velocity

u=initial velocity

a=acceleration

s=displacement

[tex]v^2-0=2\times 0.476\times 10[/tex]

[tex]v=\sqrt{9.52}[/tex]

[tex]v=3.08 m/s[/tex]