Kinetics and Dynamics 2 questions?

Question

1) An aircraft enters a 75° horizontal turn at 210 kmhr and exits at 170 kmhr. the turn takes 2.3s. calculate:

i) the change in velocity
ii) the average acceleration

2) A fly sits on the edge of a 175mm diameter 45 r.p.m vinyl record. what acceleration does it experience (magnitude and direction)? Confused, it flies to the edge of a 350mm diameter 33r.p.m disk. Is this less stressful? It tires and lets go without flying. Sketch its subsequent trajectory and calculate its speed.

Answer 1

1.
i) dV=170 - 210= -40 km/h angle of 75 deg.
ii) a= dV/t=( -40 x 3.6)/2.3=-62.6 m/s^2

2. a= V^2/R
V= 2pi R rpm/60
V1=2 pi .175x 45/60=0.825 m/s
V2= 2 pi .35 x 33/60=1.21 m/s
a1= (0.825)^2/0.175=3.89 m/s^2
a2=(1.21)^2/0.35=4.18m/s^2