How Far and How Fast Does the 25 kg Block Move?

In summary, a pulley can change the direction of motion and also increase or decrease acceleration. There are two types of pulleys: fixed and movable. A fixed pulley only changes the direction of the applied force, while a movable pulley can increase the mechanical advantage. The mechanical advantage of a pulley system is calculated by dividing the output force by the input force. A pulley system can decrease the acceleration of an object if the mechanical advantage is greater than one. Friction can decrease the efficiency of a pulley system, resulting in a decrease in mechanical advantage and an increase in force needed to move the object. To minimize the effects of friction, pulleys should be well lubricated and ropes or cables should be in good condition.
  • #1
cdirk11
2
0
A 25 kg block on a table with a pulley attached, slides along a frictionless surface. It is connected by a massless string to a 5.9 kg block hanging straight down off the table. Find the horizontal distance the 25 kg block moves when the 5.9 kg block descends a distance of .102 m. Also find the acceleration of the 25 kg block.
 
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  • #2
You could use

Newton's 2nd Law

[tex] \sum^{n}_{i=1} \vec{F}_{i} = m \vec{a} [/tex]

and

[tex] W = \Delta K [/tex]
 
  • #3


To find the horizontal distance the 25 kg block moves, we can use the equation d = (m2/m1) * h, where d is the horizontal distance, m1 is the mass of the hanging block, m2 is the mass of the sliding block, and h is the vertical distance the hanging block descends. Plugging in the given values, we get d = (5.9 kg/25 kg) * 0.102 m = 0.024 m.

To find the acceleration of the 25 kg block, we can use the equation a = (m2*g)/(m1 + m2), where a is the acceleration, m1 is the mass of the hanging block, m2 is the mass of the sliding block, and g is the acceleration due to gravity. Plugging in the given values, we get a = (5.9 kg*9.8 m/s^2)/(25 kg + 5.9 kg) = 0.774 m/s^2.

Therefore, the 25 kg block will move a horizontal distance of 0.024 m and will experience an acceleration of 0.774 m/s^2. This is because the hanging block exerts a force on the sliding block through the string, causing it to accelerate horizontally. The motion of the pulley also plays a role in the acceleration of the sliding block.
 

FAQ: How Far and How Fast Does the 25 kg Block Move?

1. How does a pulley affect motion and acceleration?

A pulley can change the direction of motion and also increase or decrease acceleration. When a rope or cable is wrapped around a pulley, it creates a mechanical advantage which can either increase or decrease the force needed to move an object. This can also affect the acceleration of the object, depending on the direction of the applied force and the number of pulleys being used.

2. What is the difference between fixed and movable pulleys?

A fixed pulley is attached to a stationary object and only changes the direction of the applied force. In contrast, a movable pulley is attached to the object being moved and can increase the mechanical advantage, resulting in a decrease in the amount of force needed to move the object. This can also affect the acceleration of the object.

3. How is the mechanical advantage of a pulley system calculated?

The mechanical advantage of a pulley system is calculated by dividing the output force (the weight of the object being moved) by the input force (the force applied to the rope or cable). The number of pulleys being used also affects the mechanical advantage, with each additional pulley increasing the mechanical advantage by one.

4. Can a pulley system ever decrease the acceleration of an object?

Yes, a pulley system can decrease the acceleration of an object if the mechanical advantage is greater than one. This means that the force needed to move the object is less than the weight of the object, resulting in a slower acceleration. However, if the mechanical advantage is less than one, the acceleration will increase as more force is needed to move the object.

5. How does friction affect pulley motion and acceleration?

Friction can decrease the efficiency of a pulley system, resulting in a decrease in the mechanical advantage and an increase in the force needed to move the object. This can also affect the acceleration of the object, as more force is needed to overcome the friction. To minimize the effects of friction, pulleys should be well lubricated and the ropes or cables should be in good condition.

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