An object of mass 1.5 kg is moving forwards along the floor against an applied force of 40.0 N [backwards]. If the coefficient of kinetic friction is 0.25, determine the
acceleration of the object.

The acceleration of the object is -29.12 m/s².

Explanation:

The acceleration of the object can be calculated by Newton's second law:

Where:

F: is the applied force = 40.0 N

μ: is the coefficient of kinetic friction = 0.25

m: is the mass of the object = 1.5 kg

g: is the acceleration due to gravity = 9.81 m/s²

a: is the acceleration =?

The minus sign is because means that the object is decelerating due to the applied force and the friction.  

Therefore, the acceleration of the object is -29.12 m/s².

I hope it helps you!  

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