Answer:
Explanation:
Given
mas of car=870 kg
coffee mug mass=0.47 kg
coefficient of static friction between mug and roof 
Coefficient of kinetic Friction 
maximum car acceleration is 
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

The answer should be flammability
True yes TRUE
Science may also be defined as the study of surroundings
As per FBD while its accelerating upwards
we can say that

here normal force is given as


now mass is given as


now we will have


Now while accelerating downwards we can say by FBD

again plug in all values

