<span>Let:
P - pushing force,
t - angle below horizontal,
F - friction force.
Resolving horizontally:
P cos(t) = F
(a)
P = F / cos(t)
= 54 / cos(30.0)
= 62.35
(b)
Work done by P
= P cos(t) * 16.0
= F * 16.0
= 54.0 * 16.0
= 864J
(c)
Work done by F
= - F * 16.0
= - 54 * 16.0
= - 864 J.
(d)
As there is no motion vertically, the work done by the gravitational force is
0.</span>
<span> </span>
Answer:
a) 433.96 miles/hr
193.98 m/s
b) 3899.3 Hz
c) 2.56 x 10^-4 ![s^{-1}](https://tex.z-dn.net/?f=s%5E%7B-1%7D)
0.015 ![m^{-1}](https://tex.z-dn.net/?f=m%5E%7B-1%7D)
Explanation:
wavelength of the tsunami = 470 miles
Distance traveled = 2300 miles
time taken to travel this distance = 5.3 h
a) wave's speed = distance/time
==> 2300/5.3 = 433.96 miles/hr
1 miles/hr = 0.447 m/s
433.96 miles/hr = 433.96 x 0.447 = 193.98 m/s
b) frequency of a wave f = speed/wavelength
for wavelength, 470 miles = 470 x 1609.34 = 756389.8 m
frequency = 756389.8/193.98 = 3899.3 Hz
c) Period T = 1/frequency
T = 1/3899.3 = 2.56 x 10^-4 ![s^{-1}](https://tex.z-dn.net/?f=s%5E%7B-1%7D)
60 sec = 1 min
Period T in sec = 2.56 x 10^-4 x 60 = 0.015 ![m^{-1}](https://tex.z-dn.net/?f=m%5E%7B-1%7D)
When the diver reaches maximum height, the upward velocity will be zero.
We shall use the formula
v^2 = u^2 - 2gh
where
v = 0 (velocity at maximum height)
u = 1.2 m/s, intial upward velocity
g = -9.8 m/s^2, gravitational acceleration (downward)
h = maximum height attained above the diving board.
Therefore
0 = 1.2^2 - 2*9.8*h
h = 1.2^2/(2*9.8) = 0.0735 m
Answer: 0.074 m (nearest thousandth)
Answer:
the only one of these materials that allows studying processes of a very long period of time is Uranium 238
Explanation:
In a radioactive material, half of the atoms decay each life period, in carbon 14 this period T = 5730 years, so for a time of 40,000 years there are 7 life periods, so there are very few atoms left without decomposing .
To study older samples, materials with a longer life period are needed, let's show the visa time
²³⁸U T= 4.5 10¹⁰ years
⁹¹Rb T = 58 s
¹³¹I T= 8.04 days
⁶⁰Co T= 5.27 years
Therefore, the only one of these materials that allows studying processes of a very long period of time is Uranium 238
Speedometer tells you how fast your going and odometer is how many miles u drive