How Do Physics Principles Determine the Outcome in Log and Elevator Scenarios?

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In summary: So the weight of this elevator lifted 35 meters would be (1200*9.8) * 35, or 411,600 joules. The tension in the cable is constant, and is equal to the weight of the elevator plus the force required to accelerate it at the desired rate. Assuming the elevator is moving at a constant velocity, there is no acceleration, so the total force exerted by the cable is simply equal to the weight of the elevator. Therefore, the work done by the tension in the cable is also 411,600 joules.In summary, the problem involves a log floating on swiftly moving water and a stone dropped from a 75-meter high bridge landing on the log. The log
  • #1
eureka360
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hi guys.. can i ask you about this problem?
A log is floating on swiftly moving water. A stone is dropped from rest from a 75meter high bridge and lands on the log as it passes under the bridge. If the log moves with a constant speed of 5 meters per second, what is the horizontal distance between the log and the bridge when the stone is released?
 
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A cable lifts a 1200kilogram elevator at a constant velocity for a distance of 35 meters. What is the work done by:
a.) the tension in the cable
b.)the elevators weight?
 
  • #3
eureka360 said:
hi guys.. can i ask you about this problem?
A log is floating on swiftly moving water. A stone is dropped from rest from a 75meter high bridge and lands on the log as it passes under the bridge. If the log moves with a constant speed of 5 meters per second, what is the horizontal distance between the log and the bridge when the stone is released?

A cable lifts a 1200kilogram elevator at a constant velocity for a distance of 35 meters. What is the work done by:
a.) the tension in the cable
b.)the elevators weight?

Please post homework problems in the appropriate homework sections, e.g. Introductory Physics.

Weight is nothing more than m*g, where m is mass and g is acceleration due to gravity. Work is the integral of force over distance, or simply product of force * distance, if force is constant over the distance.
 

Related to How Do Physics Principles Determine the Outcome in Log and Elevator Scenarios?

1. How does the elevator in a building work?

The elevator in a building works by using a system of cables, pulleys, and a motor to lift and lower a cab or car. The motor turns a gear which then rotates a drum, and the cables are connected to the drum. The cab is attached to the cables and moves up and down as the drum rotates.

2. Why do logs float in water?

Logs float in water because of their density. The density of water is 1 gram per cubic centimeter, while most types of wood have a density of less than 1 gram per cubic centimeter. This means that the wood is less dense than water, so it is able to float.

3. How does the weight of a log affect its ability to float?

The weight of a log does not directly affect its ability to float. Instead, it is the density of the log that determines whether it will float or sink. A log with a lower density will float, while a log with a higher density will sink.

4. Can a floating log sink?

Yes, a floating log can sink if its density changes. For example, if the log absorbs water and becomes waterlogged, its density will increase and it will sink.

5. How does the shape of a log affect its buoyancy?

The shape of a log does not have a significant impact on its buoyancy. As long as the log's density is less than that of water, it will float. However, logs that are more streamlined or have a larger surface area may be more stable in the water.

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