The formula for average speed is S=D/T
1. S=72m/37s
Divide
S= 1.94
Kira's average speed is 1.94m/s.
2. S=7.5km / 1.5h
S=5
Your average speed is 5km/h
3. S=1260km/3.5h
S=360
The airplanes average speed is 360km/h
17. C. Isotopes
18. Tracers
19. Alpha Decay
Time period of fan (t) = 1 / 2 = 0.5 seconds
Angular velocity (ω)= 2π/t
ω = 4π
v = ωr
v = 4π x 0.61
v = 7.66 m/s
Answer:
Acceleration 
Explanation:
We have given that the force by the motor 
Resistive force by the water 
So net force 
Mass of the boat = 1384.1 kg
According to newton's second law F=Ma, here M is mass and a is acceleration
So 
True only some changes in speed or direction are caused by forces
