Question

Under the "Applied Forces" arrow to 50 N. Watch and observe the person. Describe in detail what occurs with forces and what happens to the speed?

Answer 1

A 50 N force applied to move a box at constant velocity is balanced by a 50 N frictional force, resulting in no change in speed. Vector sum of forces is used to determine the net force when multiple forces are applied. The force of gravity and air resistance determine the motion of a parachutist.

Step-by-step explanation:

Under the concept of applied forces and Newton's First Law of Motion, when a person applies a force of 50 N to move a box at constant velocity, the force of friction opposing this motion must also be 50 N but in the opposite direction. This results in a net force of zero, indicating that the forces are balanced and the speed will not change. In a scenario involving no friction, such as an object sliding on an icy surface, once the applied force stops, the object will continue at a constant velocity due to inertia, which means that both the acceleration and speed remain constant unless acted upon by another force.

Concerning the forces on a basketball player and the ball during a jump shot, various forces are acting including gravity pulling down and the force of the player pushing upward. When two individuals push a boulder, the resulting acceleration depends on the net force and the mass of the boulder. With an archer pulling back on a bow, the speed of the arrow after release can be calculated based on the force applied and the distance over which the force is applied (Hooke's Law). When pushing a stalled car, the resultant force is the vector sum of the individual forces applied by the people pushing.

In the case of a parachutist opening their parachute, the air resistance would eventually balance with the gravitational force, leading to a constant velocity or terminal velocity during the fall. For a car accelerating due to an applied force from the engine, the net force can be found by subtracting friction forces from the applied force, and using Newton's second law, the acceleration can be determined.

Answer 2

The frictional force must equal the applied force of +50 N in the opposite direction when the motion is at constant velocity, meaning the net force is zero due to Newton's first law. Free-body diagrams help explain motion, and in a frictionless environment, when the force stops, an object's speed remains constant. When multiple forces are involved, such as in pushing a car, the resultant force is the vector sum of the individual forces.

Step-by-step explanation:

In the scenario where a man pushes a box across the floor with a force of +50 N and the box moves at a constant velocity, the frictional force opposing the motion must equal -50 N. This is because, according to Newton's first law of motion, an object moving at a constant velocity must have a net force of zero acting upon it. When analyzing movement, free-body diagrams are very useful. They allow us to visually represent forces acting on an object and explain how these forces affect the object's motion. Furthermore, by understanding the relationship between forces, we can utilize other graphs such as position, velocity, and acceleration to predict motion. For example, if an object moves on a smooth icy surface with zero friction, once the applied force stops, the object's acceleration becomes zero, but its speed remains constant due to its momentum.

Drawing from another example, if the net external force on a 24-kg mower is 51 N and the force of friction is 24 N, the force exerted by the person on the mower is 75 N (51 N + 24 N). After the force is removed when the mower is moving at 1.5 m/s, it will eventually stop due to the continuous force of friction exerting a negative acceleration.

When dealing with combined forces, such as with two people pushing a car, the resultant force on the car is found by adding the individual forces together in a specific direction, which in the example is a combined force of 95 N.