A 10.0 kg box is pulled along a horizontal surface by a force of 40.0 N applied at a 30.0° angle. If the coefficient of kinetic friction is 0.30. Calculate the acceleration.

Respuesta :

Answer:

Explanation:

Given

mass of box [tex]m=10\ kg[/tex]

Force applied [tex]F=40 \N[/tex]

inclination of force [tex]\theta =30^{\circ}[/tex] (w.r.t horizontal)

coefficient of kinetic friction [tex]\mu _k=0.3[/tex]

Net Normal reaction on the box is

[tex]N=mg-F\sin \theta [/tex]

Friction force [tex]f_r=\mu _kN[/tex]

[tex]f_r=0.3(10\times 9.8-40\times \sin 30)[/tex]

[tex]f_r=23.4\ N[/tex]

force which is moving the box

[tex]F\cos \theta [/tex]

Net force on the block

[tex]F\cos \theta -f_r=ma[/tex]

[tex]40\times \cos 30-23.4=10\times a[/tex]

[tex]a=1.12\ m/s^2[/tex]

Answer:

1.66 m/s²

Explanation:

mass of box, m = 10 kg

Force, F = 40 N

Angle of inclination, θ = 30°

coefficient of friction, μ = 0.3

Let N be the normal reaction,

equilibrium of force in y axis

N + F Sinθ = mg

N = 10 x 9.8 - 40 Sin 30

N = 98 - 20 = 78 N

Friction force, f = μN = 0.3 x 78 = 23.4 N

Now, use Newton's second law in X axis

F - f = ma

where, a be the acceleration

40 - 23.4 = 10 x a

a = 1.66 m/s²

Thus, the acceleration is 1.66 m/s².