Upon impact, bicycle helmets compress, thus lowering the potentially dangerous acceleration experienced by the head. a new kind of helmet uses an airbag that deploys from a pouch worn around the rider’s neck. in tests, a headform wearing the inflated airbag is dropped onto a rigid platform; the speed just before impact is 6.0 m/s. upon impact, the bag compresses its full 12.0 cm thickness, slowing the headform to rest. what is the acceleration, in g’s, experienced by the headform?

-15.3g

Explanation:

We can find the acceleration by using the following SUVAT equation:

where:

v = 0 is the final velocity (the headform comes to rest)

u = 6.0 m/s is the initial velocity before the impact

d = 12.0 cm = 0.12 m is the distance covered during the impact

a is the acceleration

Solving for a, we get

Where the negative sign means it is a deceleration.

Now we know that

So we can express the acceleration in units of g:

-first use of geothermal energy occurred more than 10,000 years ago in north america by american paleo-indians

-the first industrial use of geothermal energy began near pisa, italy in late 18th century

-in 1904, italian scientist piero ginori conti invented the first geothermal electric power plant in which steam was used to generate the power

-with the above experiment, the first geothermal plant in usa started in 1922 with a capacity of 250 kilowatts

-however, in 1946 first ground-source geothermal heat pump installed at commonwealth building in portland, oregon

-during the 1960’s, pacific gas and electric began operation of first large scale geothermal power plant in san francisco, producing 11 megawatts

-in 1973, when oil crisis began many countries began looking for renewable energy sources and by 1980’s geothermal heat pumps (ghp) started gaining popularity in order to reduce heating and cooling costs

-as effect of climate change started showing results, governments of various countries joined hands to fight against it, for which kyoto protocol was signed in japan in 1997, laid out emission targets for rich countries and required that they transfer funds and technology to developing countries, 184 countries have ratified it

hope this