Dynamics Questions: Spring Scale and Fire Helicopter

  • Thread starter Thread starter rabedes
  • Start date Start date
  • Tags Tags
    Dynamics
AI Thread Summary
The discussion focuses on two physics problems involving dynamics. The first scenario examines a 73.0 kg man on a spring scale in an elevator, analyzing the scale's readings during different phases of the elevator's motion: at rest, during acceleration, at constant speed, and while decelerating. The second scenario involves a fire helicopter carrying a 615 kg bucket of water, requiring calculations of air resistance and the mass of water when the bucket's angle changes. Both problems emphasize the application of Newton's second law, F = ma, to derive the necessary forces and mass. Understanding these concepts is essential for solving dynamics questions effectively.
rabedes
Messages
1
Reaction score
0
A 73.0 kg man stands on a spring scale in an elevator. Starting from rest, the elevator ascends, attaining its maximum speed of 1.14 m/s in 0.900 s. It travels with this constant speed for the next 5.00 s. The elevator then undergoes a uniform acceleration in the negative y direction for 2.00 s and comes to rest.

(a) What does the spring scale register before the elevator starts to move?
(b) What does it register during the first 0.900 s?
(c) What does it register while the elevator is traveling at constant speed?
(d) What does it register during the time it is slowing down?

and ...

A fire helicopter carries a 615 kg bucket of water at the end of a cable 19.0 m long. As the aircraft flies back from a fire at a constant speed of 39.5 m/s, the cable makes an angle of 45.0° with respect to the vertical.

(a) Determine the force of air resistance on the bucket
(b) After filling the bucket with sea water, the helicopter returns to the fire at the same speed with the bucket now making an angle of 6.00° with the vertical. What is the mass of the water in the bucket?

please help me out. thanks!
 
Physics news on Phys.org
So what you've done for this problem? You just use the Newton's second law \vec{F} = m\vec{a} to solve these two problems :)
 
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
Back
Top