- #1
troy611
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i am confused about the exact forces in play while we walk and while a car is driven, can anybody please show me a free body diagram regarding these with explanation? Also, which force does work when we walk?
Thnx
Thnx
Forces while walking and driving
- Thread starter troy611
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In summary, the forces at play while walking and driving a car include friction against the ground, as well as the knee always being slightly flexed while walking and the use of three fulcrums in the human body. While the traditional belief is that the hub is the fulcrum in a car wheel, there is a different perspective that the hub is actually the load arm, with the axel effort and tire circumference serving as the fulcrum.
- #2
tiny-tim
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Welcome to PF!
Hi troy611! Welcome to PF!
Friction against the ground, in both cases.
(plus, in normal walking mode, though not essential, falling very slightly onto each succeeding step)
You tell us … how is work done defined?
Hi troy611! Welcome to PF!
troy611 said:
Friction against the ground, in both cases.
(plus, in normal walking mode, though not essential, falling very slightly onto each succeeding step)
You tell us … how is work done defined?
- #3
boit
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The knee is always slightly flexed when walking. Also there are three fulcrum in human body as a machine, ankle joint, knee joint and hip joint. the pelvis also rotates in an important way. In a car wheel there is only one fulcrum traditionaly believed to be the hub. I have my own idea where the fulcrum should be. To me the hub is actually the load arm, axel effort and tire circumference the fulcrum. This observation though is not so popular
- #4
troy611
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ohk...thanks everyone for helping out
- #5
PJC01
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for the question! Walking and driving involve multiple forces that act on our bodies and the objects we are moving. Let's start with walking. When we walk, our legs push against the ground, creating a reaction force from the ground pushing back on our feet. This is known as the normal force and it is represented by the blue arrow in the free body diagram. Additionally, we also have the force of gravity pulling us down towards the center of the Earth, represented by the red arrow. These two forces are balanced, creating a net force of zero, allowing us to maintain a constant speed while walking.
Now, let's move on to driving. When a car is being driven, the engine provides a force that propels the car forward, represented by the green arrow in the free body diagram. This force is countered by the friction force between the tires and the road, represented by the orange arrow. The direction of the friction force depends on the direction of the car's motion. If the car is moving forward, the friction force will act in the opposite direction, slowing down the car. If the car is moving in reverse, the friction force will act in the same direction, helping to slow down the car. Other forces at play while driving include the force of air resistance, which can be represented by the purple arrow.
As for which force does work when we walk, it is the force of gravity. Work is defined as the product of force and displacement. When we walk, we are constantly lifting our bodies against the force of gravity, which requires work to be done. This is why we feel tired after a long walk, as our muscles have done work against the force of gravity.
I hope this free body diagram and explanation have helped to clarify the forces at play while walking and driving. Keep exploring and asking questions!
Now, let's move on to driving. When a car is being driven, the engine provides a force that propels the car forward, represented by the green arrow in the free body diagram. This force is countered by the friction force between the tires and the road, represented by the orange arrow. The direction of the friction force depends on the direction of the car's motion. If the car is moving forward, the friction force will act in the opposite direction, slowing down the car. If the car is moving in reverse, the friction force will act in the same direction, helping to slow down the car. Other forces at play while driving include the force of air resistance, which can be represented by the purple arrow.
As for which force does work when we walk, it is the force of gravity. Work is defined as the product of force and displacement. When we walk, we are constantly lifting our bodies against the force of gravity, which requires work to be done. This is why we feel tired after a long walk, as our muscles have done work against the force of gravity.
I hope this free body diagram and explanation have helped to clarify the forces at play while walking and driving. Keep exploring and asking questions!
What is the difference between walking and driving in terms of forces?
Walking and driving both involve the application of forces, but the main difference is that walking relies on the force of friction and driving relies on the force of propulsion. When we walk, our feet push against the ground and the friction between our feet and the ground allows us to move forward. When we drive, the force of the car's engine propels the car forward.
How does the force of gravity affect walking and driving?
The force of gravity affects both walking and driving. When we walk, gravity pulls us towards the ground and we must use our muscles to overcome this force and stay upright. When we drive, gravity still pulls us towards the ground, but the force of the car's engine counteracts this force and allows us to stay on the road.
How does friction play a role in walking and driving?
Friction is crucial in both walking and driving. When we walk, the friction between our feet and the ground allows us to push off and move forward. When we drive, the friction between the tires and the road allows the car to grip the road and move forward without slipping or sliding.
What other forces are involved in walking and driving?
In addition to friction and gravity, there are other forces that play a role in walking and driving. These include inertia, which is the tendency of an object to resist changes in motion, and air resistance, which affects objects moving through the air, such as a car driving at high speeds.
How do different surfaces affect the forces involved in walking and driving?
The surface we walk or drive on can greatly affect the forces involved. For example, walking on a slippery surface like ice requires more force to maintain balance and propel ourselves forward. Driving on a rough or uneven surface can also require more force to maintain control of the car.
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