How Does Tension Affect a Cord?

What is a Heavy Steel Ball Suspended from a Block of Wood?

A heavy steel ball b suspended by cord from block of wood w is a simple, yet effective experiment that demonstrates the principles of gravity and inertia. The weight of the ball causes it to remain in a stationary position, while the block of wood keeps it suspended in mid-air. The experiment can be used to demonstrate the effects of gravity on objects of different mass and how the same force can be used to create different results. It is also a great way to understand the principles of inertia, or how objects in motion tend to stay in motion.

Let us first consider the free-fall scenario. If the cord and wood block are free from resistance to the falling ball, there will be zero tension in the cord. However, if the wood block offers some resistance, there will be some tension in the cord.

Object

Consider a situation where a heavy steel ball is suspended by a cord from a block of wood. Assume that the weight of the ball is approximately equal to the mass of the wood block. As the block drops, the entire system will be subjected to a tension of the cord due to the resistance of air.

First, consider the initial situation of the system. Assume that the wood block is stationary before the collision occurs. Next, imagine that the bullet is moving from a stationary position to the point of impact. Assume that the bullet travels at a speed equal to the height below the lowest position. Now, take this information and combine it with the initial and final state of the system. You can then calculate the post-collision speed of the wood block and bullet by using the energy conservation equation.

Another example is a car engine with a mass m supported by an ideal pulley. The mass of the engine is m. The final velocity will be the same as m. The distance from A to B is 9 meters. The resulting final velocity will be the product of the initial velocity and the distance traveled.

Air resistance

Suppose a heavy steel ball B is suspended by a cord from a block of wood W. If the ball falls freely, the tension on the cord is equal to the difference between the mass of B and the weight of W. However, what happens when the ball is dropped? In this situation, the weight of B and the cord are all accelerated uniformly.

Assume the mass of the ball is 1.0 kg, and the weight is four kilograms. If the mass is 4.0 kg, it will drop 1.0 kg, and hit the floor with a speed of 1.0 m/s. Another simple experiment would be to suspend a large steel ball from a cord suspended from a block of wood.

Negligible air resistance

A heavy steel ball B is suspended by a cord from a block of wood W and dropped into the air. If the air resistance is negligible, the weight of B and the weight of the cord will fall to the ground in a uniform manner. This is known as the free-fall scenario.