Apply a force to the crate by pushing on it, then stop pushing once it starts to move.
Describe how the speed of the crate changes once it is no longer being pushed by the person when friction is present.
When the person stops pushing the crate, the forces acting on it change. At that point, the only force acting on the crate is the force of friction between the crate and the ground, which opposes the direction of motion. This force will cause the speed of the crate to decrease over time as the crate comes to a stop. The rate of deceleration will depend on the strength of the frictional force and the mass of the crate. Therefore, as the crate moves on the ground, the friction force slows it down until it eventually comes to a stop.
When the crate is no longer being pushed by the person, its motion is influenced by the force of friction. Friction is a force that opposes the motion between two surfaces in contact. In this case, the crate is in contact with the ground, and the friction between the crate and the ground acts in the opposite direction to its motion.
Initially, when the person applies a force to the crate by pushing on it, the force of friction is greater than or equal to the force applied by the person, resulting in the crate not moving or moving with a slow acceleration. This is because the frictional force opposes the applied force and balances it out, leading to no net force acting on the crate.
Once the applied force exceeds the force of friction, the crate overcomes static friction and starts to move. At this point, the speed of the crate increases, and it undergoes a period of acceleration. However, the force of friction continues to act, opposing the motion of the crate. The magnitude of the frictional force depends on the coefficient of friction between the crate and the surface it is on, as well as the normal force exerted on the crate.
As the crate moves, the force of friction remains constant, as long as the conditions and the coefficient of friction do not change. This means that the crate experiences a constant opposing force that slows down its acceleration and eventually brings it to a stop.
Therefore, the speed of the crate will gradually decrease over time as the force of friction continually acts against its motion. Eventually, if the person does not apply any additional force, the crate will come to a complete stop. The rate at which the speed decreases depends on the coefficient of friction and other factors that affect friction, such as the levelness of the surface or the presence of any other external forces.
When the person applies a force to the crate by pushing on it, the crate initially remains at rest due to the static friction between the crate and the surface it is on. As the person continues to push with enough force, eventually the static friction is overcome, and the crate starts to move. Once the crate is in motion, it experiences kinetic friction, which opposes the motion of the crate.
When the person stops pushing on the crate, the only force acting on it now is the kinetic friction. This frictional force always opposes the motion of the crate and acts in the opposite direction to its velocity. As a result, the speed of the crate gradually decreases over time. The crate will eventually come to a stop if no external force is applied to keep it moving.
The decrease in speed is due to the work done by the kinetic friction. This work converts the kinetic energy of the moving crate into heat, dissipating the energy and causing the crate to slow down. The amount by which the speed decreases depends on the magnitude of the frictional force and the mass of the crate.