Net Force Physics Problems With Frictional Force and Acceleration
TLDRThis video script presents a series of physics problems focused on calculating net force and acceleration in various scenarios. It begins with a 5 kg box experiencing a net horizontal force, leading to a detailed explanation of Newton's second law and how to calculate the box's acceleration and displacement. The script then progresses to more complex situations, including a box with an applied force at an angle and a car accelerating from 25 m/s to 60 m/s, demonstrating how to find the net force and the average force exerted by the engines against friction. Each problem is methodically solved, providing clear insights into the principles of force and motion.
Takeaways
- 📚 The net horizontal force on a 5 kg box pulled by 200 N is 140 N, considering 60 N friction.
- 🚀 The acceleration of the 5 kg box is 28 m/s², derived from Newton's second law (F=ma).
- 🛤️ The 5 kg box will travel 3.15 km in 15 seconds when starting from rest with the given acceleration.
- 🔢 For a 12 kg box pulled by a 350 N force at 30 degrees above horizontal, the net horizontal force is 183.1 N.
- 🏎️ The acceleration of the 12 kg box is 15.26 m/s², calculated using the net horizontal force and mass.
- 🏁 The final speed of the 12 kg box after traveling 200 meters is 78.1 m/s.
- 🚗 A 1200 kg car accelerates from 25 m/s to 60 m/s in 5 seconds, resulting in an acceleration of 7 m/s².
- 🌟 The net force acting on the car is its mass times the acceleration, equaling 8400 N.
- 💥 The average force exerted by the car's engines, overcoming friction, is 11900 N.
- 📐 The applied force can be determined by adding the net force and frictional force, then solving for the engine force.
- 📈 The script demonstrates the application of Newton's laws and kinematic equations to solve physics problems involving forces and motion.
Q & A
What is the mass of the first box in the physics problem?
-The mass of the first box is 5 kilograms.
What is the horizontal force applied to the right on the 5 kg box?
-The horizontal force applied to the right on the 5 kg box is 200 newtons.
What is the frictional force opposing the motion of the 5 kg box?
-The constant frictional force opposing the motion of the 5 kg box is 60 newtons.
How is the net horizontal force on the 5 kg box calculated?
-The net horizontal force on the 5 kg box is calculated by subtracting the frictional force from the applied force: 200 N - 60 N = 140 N.
What is the acceleration of the 5 kg box?
-The acceleration of the 5 kg box is determined by dividing the net force by the mass: 140 N / 5 kg = 28 m/s².
How far will the 5 kg box travel after 15 seconds?
-The 5 kg box will travel 3150 meters, or 3.15 kilometers, after 15 seconds.
What is the angle of the applied force for the 12 kg box?
-The applied force for the 12 kg box is 30 degrees above the horizontal.
What are the components of the 350 N force acting on the 12 kg box?
-The components of the 350 N force are f_x = 350 N * cos(30°) and f_y = 350 N * sin(30°).
What is the net horizontal force on the 12 kg box?
-The net horizontal force on the 12 kg box is 183.1 newtons.
What is the final speed of the 12 kg box after traveling 200 meters?
-The final speed of the 12 kg box after traveling 200 meters is 78.1 meters per second.
What is the acceleration of the 1200 kg car?
-The acceleration of the 1200 kg car is 7 meters per second squared.
What is the average force exerted by the engines on the 1200 kg car, considering the constant frictional force?
-The average force exerted by the engines on the 1200 kg car, accounting for the frictional force, is 11900 newtons.
Outlines
📐 Calculating Net Force and Acceleration on a Box
In this segment, we tackle a physics problem involving a 5 kg box subjected to a 200 N force to the right and a 60 N frictional force to the left. By analyzing the forces, we determine the net horizontal force is 140 N. Utilizing Newton's second law, we calculate the acceleration of the box to be 28 m/s². Finally, we apply kinematic equations to find that the box will travel 3.15 km after 15 seconds, assuming it starts from rest.
📐 Analyzing Forces and Motion for a Box with an Inclined Force
The second paragraph introduces a problem with a 12 kg box experiencing a 350 N force at a 30-degree angle above the horizontal and a 120 N frictional force. We resolve the applied force into its x and y components, focusing on the x-component to find the net horizontal force. The calculation yields a net force of 183.1 N. Using Newton's second law again, we find the box's acceleration to be 15.26 m/s². With the acceleration and an initial speed of zero, we use the kinematic equation to find the final speed of the box after traveling 200 meters, which is determined to be 78.1 m/s.
🚗 Calculating Acceleration and Force for a Speeding Car
The final paragraph deals with a 1200 kg car accelerating from 25 m/s to 60 m/s over 5 seconds. We calculate the car's acceleration using the formula v_final = v_initial + a*t, resulting in an acceleration of 7 m/s². To find the net force acting on the car, we multiply the car's mass by its acceleration, yielding a net force of 8400 N. If the car experiences a constant frictional force of 3500 N, we determine the average force exerted by the engines on the car by adding the net force and the frictional force, resulting in an applied force of 11900 N.
Mindmap
Keywords
💡Net Force
💡Frictional Force
💡Acceleration
💡Newton's Second Law
💡Kinematic Problems
💡Components of Force
💡Displacement
💡Final Speed
💡Applied Force
💡Mass
Highlights
Calculation of net horizontal force on a 5 kg box pulled by 200 N force and opposed by 60 N friction begins at the start of the video.
The net horizontal force acting on the 5 kg box is found to be 140 N by subtracting the frictional force from the applied force.
Newton's second law is introduced to calculate the acceleration of the 5 kg box, resulting in an acceleration of 28 m/s^2.
The displacement of the 5 kg box after 15 seconds is calculated to be 3150 meters or 3.15 kilometers.
A 12 kg box is subject to a 350 N force at a 30-degree angle above the horizontal and opposed by 120 N friction in the next problem.
The net horizontal force on the 12 kg box is determined to be 183.1 N by considering the x-component of the applied force.
The acceleration of the 12 kg box is calculated to be 15.26 m/s^2 using the net horizontal force and the box's mass.
The final speed of the 12 kg box after traveling 200 meters is found to be 78.1 m/s by applying the kinematic equation.
A 1200 kg car's acceleration is calculated from its speed up from 25 m/s to 60 m/s in 5 seconds, resulting in an acceleration of 7 m/s^2.
The net force acting on the car is determined to be 8400 N by multiplying the car's mass with its acceleration.
The average force exerted by the car's engines, considering a constant frictional force of 3500 N, is calculated to be 11900 N.
The video demonstrates the application of Newton's laws and kinematic equations to solve for various motion-related parameters.
The method of breaking down forces into their components is illustrated using the example of the 12 kg box with an angled force.
The concept of initial and final states in kinematics is utilized to calculate distance traveled and final speed.
The importance of considering frictional forces in real-world physics problems is emphasized throughout the video.
The video provides a step-by-step approach to problem-solving in physics, making complex calculations accessible.
Transcripts
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