Answer:
B
Explanation:
Speed is the magnitude of the velocity vector, so it can never be negative.
Answer:
2.24 seconds
Explanation:
xf = xo + vo t + 1/2 at^2
45 = 0 + 15 t + 1/2 (4.5) t^2
2.25 t^2 + 15t - 45 = 0 Quadratic formula shows t = 2.24 seconds
Answer:
Time of flight A is greatest
Explanation:
Let u₁ , u₂, u₃ be their initial velocity and θ₁ , θ₂ and θ₃ be their angle of projection. They all achieve a common highest height of H.
So
H = u₁² sin²θ₁ /2g
H = u₂² sin²θ₂ /2g
H = u₃² sin²θ₃ /2g
On the basis of these equation we can write
u₁ sinθ₁ =u₂ sinθ₂=u₃ sinθ₃
For maximum range we can write
D = u₁² sin2θ₁ /g
1.5 D = u₂² sin2θ₂ / g
2 D =u₃² sin2θ₃ / g
1.5 D / D = u₂² sin2θ₂ /u₁² sin2θ₁
1.5 = u₂ cosθ₂ /u₁ cosθ₁ ( since , u₁ sinθ₁ =u₂ sinθ₂ )
u₂ cosθ₂ >u₁ cosθ₁
u₂ sinθ₂ < u₁ sinθ₁
2u₂ sinθ₂ / g < 2u₁ sinθ₁ /g
Time of flight B < Time of flight A
Similarly we can prove
Time of flight C < Time of flight B
Hence Time of flight A is greatest .
The sound level of the sound wave due to the ambulance is 140.
<h3>What do you mean by sound?</h3>
In terms of physics, the sound is a vibration that travels through a transmission medium like a gas, liquid, or solid as an acoustic wave. Sound is the reception of these waves and the brain's perception of them in terms of human physiology and psychology. Only acoustic waves with frequencies between roughly 20 Hz and 20 kHz, or the audio frequency range, can cause a human to have an auditory sensation. These are sound waves with wavelengths ranging from 17 meters (56 ft) to 1.7 millimeters in the air at atmospheric pressure (0.67 in). Ultrasounds are sound waves with a frequency higher than 20 kHz that are inaudible to humans. Infrasound refers to sound frequencies below 20 Hz. Animals of different species have different hearing ranges.
To learn more about sound, Visit:
brainly.com/question/9349349
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