Let
V the speed of the girl per step
v the speed of the escalator per step
L the length between ground and floor in number of steps
V*60+v*60=L => V+v=L/60
V*90-v*90=L => V-v=L/90
By adding the equations V+v=L/60 and V-v=L/90 we get:
2V=L(3+2)/180
V=5L/360
V = L/72
Time to climb (in steps) with v=0 (escalator standing still) is:
V*t=L
t = L/V
t = L/(L/72)
t =72 steps
The girl will count 72 steps.
Answer:
Wave frequency does not affect wave speed. An increase in wave frequency caused a decrease in wavelength while the wave speed remained constant. ... Rather, the speed of the wave is dependent upon the properties of the medium such as the tension of the rope.
Answer:
B. Some systems monitor EGR operation using a manifold absolute pressure (MAP) sensor.
Explanation:
The Manifold Absolute Pressure (MAP) sensor is a device used to measure absolute pressure inside the engine, it is used to calculate gas quantity needed to be injected into the cylinder and also for engine load input by the powertrain control module (PCM).
It is not used with the EGR as a monitor.
Answer:
375 ms
Explanation:
the frequency of metronome , f = 160 beats per minute
f = 160 /60 beats per sec
f = 2.67 beats /s
the period of a single beat , T = 1/f
T = 1/2.67 s
T = 0.375 s = 375 ms
the period of a single beat is 375 ms
