A skateboarder is traveling at a constant speed to the left. Suddenly, two forces start acting on him - one 5 N force to the front and one 5 N force to the back. Which describes the motion of the skateboarder when those two forces suddenly act on him?
forces cancel, motion unchanged.
When the skateboarder is traveling at a constant speed to the left, it means that there is no overall net force acting on the skateboarder. However, when the two forces (5 N to the front and 5 N to the back) suddenly act on him, there is now a net force acting on the skateboarder.
Since the two forces have the same magnitude (5 N) and are acting in opposite directions (front and back), they cancel each other out. This means that the net force acting on the skateboarder is zero N.
According to Newton's first law of motion, an object will continue to move with a constant velocity (in this case, constant speed to the left) when the net force acting on it is zero. Therefore, the skateboarder will continue to move at a constant speed to the left when the two forces suddenly act on him.
To understand the motion of the skateboarder when the two forces act on him, we need to consider the net force acting on him. The net force is the vector sum of all the forces acting on an object.
In this case, there are two forces acting on the skateboarder - one force 5 N to the front and one force 5 N to the back. Since the forces are equal in magnitude and opposite in direction, they cancel each other out. Therefore, the net force on the skateboarder is zero.
When the net force on an object is zero, according to Newton's first law of motion, the object will continue to move with a constant velocity. In this case, since the skateboarder was traveling at a constant speed to the left before the forces acted on him, he will continue to move at the same constant speed to the left even after the forces are applied.
So, the motion of the skateboarder remains unchanged. He will continue to move at a constant speed to the left.