Quiz

Statements about isotopes

Iteru [2.4K]

Answer:

Key Takeaways: Isotopes

Isotopes are samples of an element with different numbers of neutrons in their atoms.

The number of protons for different isotopes of an element does not change.

Not all isotopes are radioactive. Stable isotopes either never decay or else decay very slowly. ...

When an isotope decays, the starting material is the parent isotope.

Explanation:

8 0

3 years ago

A horse and rider are racing to the right with a speed of 21\,\dfrac{\text m}{\text s}21 s m 21, start fraction, start text, m

Marrrta [24]

Answer:

a=-4.2 m/s²

Explanation:

The horse riding so inital velocity is given finally the rider stops so the final velocity is zero.

initial velocity =Vi= 21 m/s

final velocity =Vf= 0 m/s

distance covered = S=52 m

By using 2nd equation of motion we can find the acceleration

2aS=Vf² -Vi²

a=(-441)/104

a=-4.2 m/s²

So the accceleration is 4.2 m/s².

7 0

3 years ago

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When a glacier moves, rocks and sediments in the bottom of the glacier scrape against the ground. This creates grooves known as

nikdorinn [45]

Answer:

D. Glacial striations

Explanation:

Glacial striations are marks and grooves carved on a rock surface as the materials carried by it abraded the surfaces of the earth.

5 0

3 years ago

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Calculate the electrical force that acts on one plate of a parallel plate capacitor. The potential difference between the plates

eduard

Answer:

The work done in bringing the plates together is 5.9 x 10⁻¹⁰ J.

Explanation:

Given;

potential difference between the plates, V = 10 V

length of each square side of the plates, L = 20 cm = 0.2 m

area of the plates, A = 0.2 x 0.2 = 0.04 m²

separation of the plates, d = 3 cm = 0.03 m

The work done in bringing the plates together is calculated as;

W = ¹/₂qV

$W = \frac{1}{2} (\frac{\epsilon_0 A }{d}V) \times V\\\\W = \frac{\epsilon_0 A V^2}{2d}\\\\W = \frac{8.85 \times 10^{-12} \ \times \ 0.04\ \times \ 10^2}{2(0.03)} \\\\W = 5.9 \times 10^{-10} \ J$

Therefore, the work done in bringing the plates together is 5.9 x 10⁻¹⁰ J.

8 0

2 years ago

A driver travels northbound on a highway at a speed of 20.0 m/s. A police car, traveling southbound at a speed of 43.0 m/s, appr

Mazyrski [523]

Answer:

Explanation:

Let the velocity of observer the driver be V₀ and the velocity of police car the source be $v_s$ . Let V be the velocity of sound in air.

The apparent frequency f is given by the following relation

$\frac{f}{F} = \frac{V+V_0}{V-V_s}$

F is real frequency.

Now F = 2600,

$V_0 = 20 ms^{-1} and\\\ V_s= 40ms^{-1}$

Putting these values in the equation

$\frac{f}{2600} = \frac{343+20}{343-43}$

f = 3146 Hz.

b ) After the police passes , the sign of velocity of observer and source get reversed.

$\frac{f}{2600} = \frac{343-20}{343+43}$

f = 2175 Hz

c ) When the police car is also going northward and trying to overtaking the driver the frequency is calculated as follows .

$\frac{f}{2600} = \frac{343-20}{343-43}$

f = 2799 Hz

When the policy car already crosses the drives the frequency will be as follows

$\frac{f}{2600} = \frac{343+20}{343+43}$

f = 2445 Hz

3 0

3 years ago