How much work would it take to horizontally accelerate an object with a mass of $8 kg$ to $3 m/s$ on a surface with a kinetic friction coefficient of $3$ ?

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Answer 1 · 2018-06-23T06:34:10

The work is $=36J$

The mass is $m=8kg$

The acceleration due to gravity is $g=9.8ms^-2$

The coefficient of kinetic friction is $mu_k=3$

The normal force is $N=mg$

The force of friction is

$F_r=mu_kN=mu_kmg$

$F=ma$

The acceleration is

$a=F/m=(mu_kmg)/m=mu_kg$

The speed is $v=3ms^-1$

The initial speed is $u=0ms^-1$

Apply the equation of motion

$v^2=u^2+2as$

The distance is

$s=v^2/(2a)=9/(2*mu_kg)=9/(2*3*9.8)=0.15m$

The work done is

$W=F*s=mu_kmg*s=3*8*9.8*0.15=36J$

How much work would it take to horizontally accelerate an object with a mass of 8 kg8 kg to 3 m/s3 m/s on a surface with a kinetic friction coefficient of 3 3 ?