Rocks tell us a great deal about the Earth's history. Igneous rocks tell of past volcanic episodes and can also be used to age-date certain periods in the past. Sedimentary rocks often record past depositional environments (e.g deep ocean, shallow shelf, fluvial) and usually contain the most fossils from past ages.

6 0

3 years ago

A 1.50-mm-diameter glass sphere has a charge of + 1.60 nC. What speed does an electron need to orbit the sphere 1.60 mm above th

saveliy_v [14]

Answer :

Velocity will be $3.28\times 10^{-11}m/sec$

Explanation:

We have given glass surface has a diameter of 1.5 mm

And charge q = 1.60 nC

Radius of electrons orbit r = height of electron above surface + radius of sphere = $=1.6+\frac{1.5}{2}=2.35mm = 0.00235m$

Force on electron is given by $F=\frac{1}{4\pi \epsilon _0}\frac{qe}{r^2}$ , here q is charge on sphere and e is charge on electron

$F=\frac{1}{4\pi \epsilon _0}\frac{qe}{r^2}=\frac{kqe}{r^2}=\frac{9\times 10^9\times 1.6\times 10^{-9}\times 1.6\times 10^{-19}}{0.00235^2}=4.172\times 10^{-13}N$

This force work as centripetal force

So $F=\frac{mv^2}{r}$

$4.172\times 10^{-13}=\frac{9.11\times 10^{-31}v^2}{0.00235}$

v = $=0.0328\times 10^{-9}=3.28\times 10^{-11}m/sec$

6 0

2 years ago

A scalar is a mathematical term for:

Iteru [2.4K]

Answer:

c. A number and a unit

Explanation:

A scalar is a real number. We often use the term scalar in the context of vectors or matrices, to stress that a variable such as a is just a real number and not a vector or matrix.

3 0

3 years ago

How?? anyone?!...........

Mariana [72]

-- find the horizontal and vertical components of F1.

-- find the horizontal and vertical components of F2.

-- find the horizontal and vertical components of F3.

-- add up the 3 horizontal components; their sum is the horizontal component of the resultant.

-- add up the 3 vertical components; their sum is the vertical component of the resultant.

-- the magnitude of the resultant is the square root of (vertical component^2 + horizontal component^2)

-- the direction of the resultant is the angle whose tangent is (vertical component/horizontal component), starting from the positive x-direction.

8 0

2 years ago