Abat crashes into the vertical front of an accelerating subway train. if the coefficient of static friction between bat and train is 0.860, what is the minimum acceleration of the train that will allow the bat to remain in place (without sliding down)?

The minimum acceleration will be                          

Explanation:

We have given that coefficient of static friction

Frictional force is given by

Weight is given by

For train to allow the bat to remain in place

So the minimum acceleration will be

a longitudinal wave moves energy that is to the direction of the wave’s movement. - true

i guess it’s a and b