Newton's Laws of Motion on a rocket

AI Thread Summary
In the discussion about Newton's Laws of Motion in the context of a rocket landing, participants analyze the forces acting on an 8.00-kg instrument hanging inside the spacecraft. A free-body diagram reveals that the weight (w = mg) acts downward while tension (T) acts upward. The key point of confusion arises from the rocket's deceleration; while the rocket is slowing down at 2.50 m/s², this upward acceleration affects the tension in the wire. The correct equation for tension is T = mg + ma, where 'a' is the upward acceleration of 2.50 m/s². Understanding this relationship clarifies the calculation of forces acting on the instrument during the rocket's landing.
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Suppose the rocket is coming in for a vertical landing at the surface of the earth. The captain adjusts the engine thrust so that rocket slows down at the rate of 2.50m/s^2 . A 8.00-kg instrument is hanging by a vertical wire inside a space ship.

1]Draw a free-body diagram for the instrument.

2]Find the force that the wire exerts on the instrument.
 
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Welcome to PF.

I wonder why you didn't use the template that is provided when you make a new post... anyway, what did you come up with?
What does your free body diagram look like? Which forces are acting on the block, in what directions and possibly magnitudes?
 
CompuChip said:
Welcome to PF.

I wonder why you didn't use the template that is provided when you make a new post... anyway, what did you come up with?
What does your free body diagram look like? Which forces are acting on the block, in what directions and possibly magnitudes?

w=mg acting on the instrument downwards. tension acting upwards. with a downward accelerating force.

my attempted ans for qn 2 is mg - T = 2.5 * 8. gives the wrong tension result...

can enlight me on where the mistake lies?
 
If the rocket is slowing, then the acceleration of the rocket is 2.5 upwards. This means that the Tension will be mg+2.5m = T = m*(g + 2.5)

Even though the ship has downward velocity - in the direction of gravity - I read it that the speed is slowing at 2.5, hence this will create a force (m*a) in addition to gravity that will add to the force of gravity in the tension on the instrument won't it?
 
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