Answer:
La aceleración del camión que parte del reposo y alcanza la velocidad de 40 km/h en 5 segundos es de 2.22 m/s².
KE=(1/2)mv² ⇒ v=√(2KE/m)
Data:
KE=kenetic energy=810 J
m=mass=80 Kg
v=velocity (speed)
v=√(2KE/m)
v=√(2*810 J/80 Kg)=4.5 m/s.
answer: his speed is 4.5 m/s.
C
I took the tests earlier hope this helps
ΔPE = mgh₂ - mgh₁= mg(h₂- h₁) = mgΔh
Answer:
about 14.7°
Explanation:
The formula for the angle of the first minimum is ...
sin(θ) = λ/a
where θ is the angle relative to the door centerline, λ is the wavelength of the sound, and "a" is the width of the door.
The wavelength of the sound is the speed of sound divided by the frequency:
λ = (340 m/s)/(1300 Hz) ≈ 0.261538 m
Then the angle of interest is ...
θ = arcsin(0.261538/1.03) ≈ 14.7°
At an angle of about 14.7°, someone outside the room will hear no sound.