Answer:
speed of the car at the bottom of the driveway is 3.8 m/s
Explanation:
given data
mass = 2.1× 10³ kg
distance = 5 m
angle = 20 degree
average friction force = 4 × 10³ N
to find out
find the speed of the car at the bottom of the driveway
solution
we find acceleration a by force equation that is
force = mg×sin20 - friction force
ma = mg×sin20 - friction force
put here value
2100a = 2100 ( 9.8)×sin20 - 4000
a = 1.447 m/s²
so from motion of equation
v²-u² = 2as
here u is 0 by initial speed and v is velocity and a is acceleration and s is distance
v²-0 = 2(1.447)(5)
v = 3.8
speed of the car at the bottom of the driveway is 3.8 m/s
Answer:
About 133 db.
Explanation:
Sound Intensity Level in db (SIL db) is equal to 10log (base 10) times the ratio of the sound intensity at 200 watts (I) relative to the sound intensity of the reference sound intensity (I sub 0), which by default is equal to 10⁻¹² W/m² or 0 dB.
I = 200 w / 10 m^2 = 20 w per square meter
I sub 0 = 10^-12 w per square meter
SIL = 10log ( I / I sub o) = 20 / 10^-12 = 10log ( 20^12) = 10 ( 13.3 ) = 133 db
Hope I typed this part correctly. Hard to get it in without being able to do exponents, etc. :D
Answer:
Beryllium
Beryllium is an alkaline metallic element that is highly toxic. It is known for its sugary sweet taste and some of its common uses are in X-rays and fluorescent lights.
Beryllium : A very thorough and technical site about this mineral.
Chromite
Chromite is the ore of chromium and is a very hard metal, and diamond is the only thing harder. This hardness is what allows a chrome finish to take a high polish.
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Cobalt
Cobalt is famous for the incredible blue color it imparts to glass and pigment. It has been found in meteorites and is used in invisible ink. It is a brittle metal and resembles iron.
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Columbite-tantalite
Columbite-tantalite group is a mineral used widely in technology. Electronics, automotive systems and health products like the pacemaker need this mineral to operate. It is mined in Africa and has earned the name of Coltan over the last few years.
Columbite-tantalite : Information about its role in the world under the name 'Coltan'.
Copper
Copper is a common metal throughout the world. It is used for currency, jewelry, plumbing and to conduct electricity. It is a soft, orange-red metal.
Copper : This site talks about its properties, uses and makeup.
Explanation:
Hope that helps :)
Answer:
Acceleration due to gravity will be 
Explanation:
We have given length of pendulum l = 55 cm = 0.55 m
It is given that pendulum completed 100 swings in 145 sec
So time taken by pendulum for 1 swing 
We have to find the acceleration due to gravity at that point
We know that time period of pendulum;um is given by

So 

Squaring both side


So acceleration due to gravity will be 
Answer:
The tension in the string is quadrupled i.e. increased by a factor of 4.
Explanation:
The tension in the string is the centripetal force. This force is given by

m is the mass, v is the velocity and r is the radius.
It follows that
, provided m and r are constant.
When v is doubled, the new force,
, is

Hence, the tension in the string is quadrupled.