# Net Torque for Constant Velocity Bike Gear Problem

• courtney1121
In summary, when going up a hill, it is better to use a lower gear or larger sprocket on a bicycle in order to maintain a constant velocity. This is because with a larger sprocket, the radius increases and the force decreases, resulting in a greater torque that can counteract the force of gravity pulling the cyclist back down the hill. This allows the cyclist to maintain a steady pace and prevent deceleration.
courtney1121
The rear wheel of a bicycle has a set of sprockets whcih vary in size. The chain hooks onto the sprockets, and when a pulling force is apply to the chain, the sprocket, hence the wheel turns. As any cyclist knows, when going up a hill, to maintain a constant velocity, it is better to use a lower gear, or larger sprocket. Why? In your answer, consider what the net torque is at constant velocity.

Ok so obviously, the larger the sprocket the easier it is to pedal, but I'm not quite sure why...I don't even know if that will apply here or not.

Any suggestions?

to explain in terms of torque...if the radius is increasing the force must decrease...causing there less force to be exerted on the pedals if the radius is large...soo should there be no net torque on the bike? how does this relate in terms of constant velocity?

courtney1121 said:
to explain in terms of torque...if the radius is increasing the force must decrease...causing there less force to be exerted on the pedals if the radius is large...soo should there be no net torque on the bike? how does this relate in terms of constant velocity?
My ankles are weaker than my wrists. It is about torque, but not less force. When going uphill, gravity is trying to pull you back down; to counteract it and move at a steady pace, without slowing because of that hill, you've got to apply more torque to keep yourself moving ahead. The idea is to apply the same force, or not much more, as when riding level, but with the increase in radius, the torque will increase even at that same force, and this increase in torque will result in keeping you from slowing, i.e., moving at constant speed rather than decelerating.

## 1. What is net torque in a constant velocity bike gear problem?

Net torque is the sum of all the torques acting on an object. In a constant velocity bike gear problem, it refers to the total torque applied to the bike's gears, which determines the bike's rotational motion.

## 2. How is net torque calculated in a constant velocity bike gear problem?

Net torque is calculated by multiplying the force applied to the gears by the distance from the point of rotation. This distance is known as the lever arm and is measured perpendicular to the direction of the force.

## 3. Why is net torque important in a constant velocity bike gear problem?

Net torque is important because it determines the rotational motion of the bike's gears. It determines the speed and direction of the bike's rotational motion, which affects the overall velocity of the bike.

## 4. How does changing gear ratios affect net torque in a constant velocity bike gear problem?

Changing gear ratios affects net torque by changing the force applied to the gears. A larger gear ratio will result in a larger force, which will increase the net torque, while a smaller gear ratio will result in a smaller force, decreasing the net torque.

## 5. Can net torque be negative in a constant velocity bike gear problem?

Yes, net torque can be negative in a constant velocity bike gear problem. This means that the torques acting in the opposite direction are greater than the torques acting in the desired direction, resulting in a net torque in the negative direction. This can cause the bike to slow down or change direction.

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