# Dynamics Queston

1. Oct 1, 2007

### rabedes

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?

2. Oct 2, 2007

### phucnv87

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 :)