Answer:
Explanation:
If the passage of the waves is one crest every 2.5 seconds, then that is the frequency of the wave, f.
The distance between the 2 crests (or troughs) is the wavelength, λ.
We want the velocity of this wave. The equation that relates these 3 things is
and filling in:
so
v = 2.5(2.0) and
v = 5.0 m/s
1. Ideal Mechanical Advantage (IMA): 9
Explanation:
For a wheel and axle system like the steering wheel, the IMA is given by:

where
is the radius of the wheel
is the radius of the axle
For the steering wheel of the problem, we see that
and
, so the IMA is

2. Efficiency: 88.9%
Explanation:
The efficiency of a system is defined as the ratio between the AMA (actual mechanical advantage) and the IMA:

In this problem, AMA=8 and IMA=9, so the efficiency is

Answer:
time taken by the wave to reach the person is 0.2 s
Explanation:
As we know that the speed of the wave is given as

here we know that the wavelength of the wave is


now speed of the wave is given as


Now time taken by the wave to reach 5 m distance is



Answer: The original temperature was

Explanation:
Let's put the information in mathematical form:





If we consider the helium as an ideal gas, we can use the Ideal Gas Law:

were <em>R</em> is the gas constant. And <em>n</em> is the number of moles (which we don't know yet)
From this, taking
, we have:
⇒
Now:
⇒
-- The acceleration due to gravity is 32.2 ft/sec² . That means that the
speed of a falling object increases by an additional 32.2 ft/sec every second.
-- If dropped from "rest" (zero initial speed), then after falling for 4 seconds,
the object's speed is (4.0) x (32.2) = <em>128.8 ft/sec</em>.
-- 128.8 ft/sec = <em>87.8 miles per hour</em>
Now we can switch over to the metric system, where the acceleration
due to gravity is typically rounded to 9.8 meters/sec² .
-- Distance = (1/2) x (acceleration) x (time)²
D = (1/2) (9.8) x (4)² =<em> 78.4 meters</em>
-- At 32 floors per 100 meters, 78.4 meters = dropped from the <em>25th floor</em>.
The 5 points are certainly appreciated, but I do wish they were Celsius points.