D
Because if an object is moving at a constant speed the force of friction must equal the applied (horizontal) force, and for it to be accelerating or decelerating, the force of friction and the applied force must be unequal
Answer:
24 N
Explanation:
= mass of the cube = 
Consider the three cubes together as one.
= mass of the three cubes together = 
= acceleration of the combination = 2 ms⁻²
= Force applied on the combination
Using Newton's second law

= Force by the left cube on the middle cube
Consider the forces acting on left cube, from the force diagram, we have

<span>120 miles is the answer
</span>
KE = 2000 J
Explanation:
KE = (1/2)mv^2
= (1/2)(0.100 kg)(200 m/s)^2
= 2000 J