Answer:
a) 36 m
b) 64 m
Explanation:
Given:
v₀ = 0 m/2
v = 12 m/s
t = 6 s
Find: Δx
Δx = ½ (v + v₀) t
Δx = ½ (12 m/s + 0 m/s) (6 s)
Δx = 36 m
The track is 100 m, so the sprinter still has to run another 64 m.
Answer:

Explanation:
From the question we are told that:
Temperature 
Intake Pressure 
Exit Pressure 
Work 
Therefore
From Table
V_f=1.01*10^{-4}
Generally the equation for isentropic Work is mathematically given by



Since
Efficiency n



Therefore

Remark
You have to pick a velocity for an ultra sound wave. I'm going to take the sound velocity to be 331 m/s in air, because I'm assuming that is what is meant: it is the sound a bat would make once he emits the ultrasound to a microphone like device that receives it. The media through which that happens is air.
Givens
v = 331m/s
f = 4 *10^4 hz
Formula
velocity = wavelength * frequency
v =
*f
331/(4*10^4) = 
0.008275 = 
8.275*10^-3 = 
Voltage = Current (I) × Resistance (R)
V = 10 × 28.5 = 285v