As per the question the mass of sled[m] is given as 8 kg.
The fictional force[tex][F_{f} ][/tex] is given as 2.4 N
A force[tex][F_{p} ][/tex] of 20 N was exerted on the sled at angle of [tex]50^{0}[/tex]
Resolving the force into horizontal and vertical components we get -
[tex]F_{h} =F_{p} cos\theta[/tex] and [tex]F_{v} =F_{p} sin\theta[/tex]
Here [tex]F_{h}[/tex] is the horizontal component and [tex]F_{v}[/tex] is the vertical component.
[tex]F_{h} =20*cos50[/tex] [tex]=12.85575219 N[/tex]
Similarly [tex]F_{v} =20*sin50=15.32088886 N[/tex]
From the free body diagram we get that sum of vertical components is zero as there is no motion in vertical direction.
Hence [tex]F_{N} +F_{p} sin\theta=mg[/tex] where g is the acceleration due to gravity .
⇒[tex]F_{N} =mg-F_{p} sin50[/tex]
⇒ [tex]F_{N} =8*9.8-15.32088886[/tex] [here value of g is 9.8 m/s^2]
=63.1 N
The net motion of the body is along the forward direction.
Hence [tex]F_{p} cos\theta -F_{f} =ma[/tex] where a is the acceleration of the body.
⇒[tex]a=\frac{F_{p}cos\theta -F_{f} }{m}[/tex]
[tex]=\frac{12.85575219 -2.4}{8}[/tex]
[tex]=1.30 m/s^2[/tex]
Hence the option A is the right answer.
