Answer :
Answer:[tex]6.86 m/s^2[/tex]
Explanation:
Given
mas of car=870 kg
coffee mug mass=0.47 kg
coefficient of static friction between mug and roof [tex]\mu _s= 0.7[/tex]
Coefficient of kinetic Friction [tex]\mu _k=0.5[/tex]
maximum car acceleration is [tex]\mu \times g[/tex]
here coefficient of static friction comes in to action because mug is placed over car . If mug is moving relative to car then \mu _k is come into effect
[tex]a_{max}=0.7\times 9.8=6.86 m/s^2[/tex]