Final answer:
The frictional force acting against the motion of the 5.0-kg block, which is accelerated by a 40 N force along a horizontal surface, is 10 N.
Step-by-step explanation:
A student has asked about the frictional force acting on a 5.0-kg block being accelerated at 6.0 m/s2 along a horizontal surface by a 40 N force. To find the frictional force, we use Newton's second law, which states that the net force acting on an object equals its mass multiplied by its acceleration, Fnet = ma. Since we have both mass (m) and acceleration (a), we can calculate the net force and then determine the frictional force using the equation Ffriction = Fapplied - Fnet.
The net force is calculated as follows: Fnet = m × a = 5.0 kg × 6.0 m/s2
= 30.0 N.
The frictional force is then: Ffriction = Fapplied - Fnet
= 40 N - 30 N
= 10 N.
Therefore, the frictional force acting against the motion of the block is 10 N.