<h2>Answer</h2>
option D)
2.4 seconds
<h2>Explanation</h2>
Given in the question,
mass of car = 1200kg
speed of car = 19m/s
Force due to direction of travel
F = ma
= 12000(a)
Force to due frictional force in reverse direction
-F = mg(friction coefficient)
= -12000(9.81)(0.8)
<h2>
-mg(friction coefficient) = ma </h2>
(cancelling mass from both side of equation)
g(0.8) = a
(9.81)(0.8) = a
a = 7.848 m/s²
<h2>Use Newton Law of motion</h2><h3>vf - vo = a • t</h3>
where vf = final velocity
vo = initial velocity
a = acceleration
t = time
0 - 19 = 7.8(t)
t = 19/7.8
= 2.436 s
≈ 2.4s
Answer:
Mass=3,height=50 and time=15,g=10,P=?
P=mgh/t....which is 3×10×50=1500/15=100Watts
Answer:
A. 0.0096 W/m²
B. 11.603 dB
C. 827.37 m/s
Explanation:
Parameters given:
Frequency, f = 274Hz
Pressure, P = 101.3 kPa
Temperature, T = 25°C = 298K
Power = 30 mW
Radial distance, = 500 mm = 0.5 m
A. Intensity = Power/Area
Intensity = Power/(4*pi*r²)
= (30 * 10^(-3))/(4 * 3.142 * 0.5²)
= 0.0096 W/m²
B. Pressure(rms) = √(I*ρ*c)
I = Intensity
ρ = density
c = speed of sound
ρ = P/RT
R = gas constant
=> ρ = (101.3 * 10^3) / (298 * 8.314)
ρ = 40.89 kg/m³
=> Pressure(rms) = √(0.0096 * 40.89 * 343)
= √(134.64)
= 11.603 dB = 11.603 * 10^(-6) Pa
C. Acoustic Particle velocity = Intensity/ Acoustic Pressure
Acoustic Particle velocity = 0.0096 / (11.603 * 10^(-6)
Acoustic Particle velocity = 827.37 m/s
A high thickness of a liquid
Answer:
if the frequency is double, the wavelength is only half as long
Explanation:
