In a pulley system, m_1m1 is 2.0kg2.0kg and m_2m2 is 1.0kg1.0kg. The coefficient of kinetic friction between m_1m1 and the table is mu_k=0.15μk=0.15. What is the acceleration of the pulley system?

1 Answer
Jun 17, 2016

2.289 ms^-22.289ms2

Explanation:

givengiven

GIVEN

  • m_1=2 kg , m_2 =1kgm1=2kg,m2=1kg
  • "Coefficient of kinetic friction between " m_1 " and table" (mu_k)=0.15Coefficient of kinetic friction between m1 and table(μk)=0.15

  • "Let"Let
    color (blue) T " be tension on string"T be tension on string
    " and " color(green) a" be the acceleration of the system " and a be the acceleration of the system

Now considering the forces on m_1m1
Normal reaction N = m_1gN=m1g
Resisting force of kinetic friction f_k=mu_kxxN=mu_km_1gfk=μk×N=μkm1g
Gravitational pull on m_1m1 being vertical to T it will not creat any resistance.

So for m_1m1 we have

T-mu_km_1g=m_1a......(1)

Considering the forces on m_2 we can write

m_2g-T=m_2a.....(2)

Adding equation (1) and equation(2) we get

m_2g-mu_km_1g=m_1a+m_2a

=>a (m_1+m_2)=(m_2-mu_km_1)g

=>a =((m_2-mu_km_1)g)/(m_1+m_2)=((1-0.15xx2)xx9.81)/(1+2)

=(0.7xx9.81)/3=2.289ms^-2