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3 years ago

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Physics

2 answers:

ikadub [295]3 years ago

6 0

All are true except the first two.

kolbaska11 [484]3 years ago

6 0

Positively charged objects attract negatively charged objects.

-PlushDna

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An electron of mass 9.11 1031 kg has an initial speed of 3.00 105 m/s. It travels in a straight line, and its speed increases to

elena55 [62]

Explanation:

It is given that,

Mass of an electron, $m=9.11\times 10^{-31}\ kg$

Initial speed of the electron, $u=3\times 10^5\ m/s$

Final speed of the electron, $v=7\times 10^5\ m/s$

Distance, d = 5 cm = 0.05 m

(a) The acceleration of the electron is calculated using the third equation of motion as :

$a=\dfrac{v^2-u^2}{2d}$

$a=\dfrac{(7\times 10^5)^2-(3\times 10^5)^2}{2\times 0.05}$

$a=4\times 10^{12}\ m/s^2$

Force exerted on the electron is given by :

$F=m\times a$

$F=9.11\times 10^{-31}\times 4\times 10^{12}$

$F=3.64\times 10^{-18}\ N$

(b) Let W is the weight of the electron. It can be calculated as :

$W=mg$

$W=9.11\times 10^{-31}\times 9.8$

$W=8.92\times 10^{-30}\ N$

Comparison,

$\dfrac{F}{W}=\dfrac{3.64\times 10^{-18}}{8.92\times 10^{-30}}$

$\dfrac{F}{W}=4.08\times 10^{11}$

Hence, this is the required solution.

8 0

3 years ago

Calculate the molecular weight of Aluminium hydroxide

Vedmedyk [2.9K]

Al(OH)3 = 26.98 + [(16×3) + (1.01×3)] = 26.98 + 51.03 = 78.01 and the unit will be g/mol

5 0

3 years ago

Two objects, A and B, each of mass o.22 kg, are moving at 0.34 m/s directly toward each other. What is the speed of Object A aft

ki77a [65]

Theoretically, if the objects have the same mass and are moving towards each other at a speed of $0.34m s^{-1}$ , after a perfectly elastic collision, the object A is supposed to move with the same velocity in the opposite direction.

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3 years ago

A hydraulic turbine is used to generate power by using the water in a dam. The elevation difference between the free surfaces up

Serjik [45]

Answer:

0.906

Explanation:

Let g = 9.81 m/s2. We can calculate the rate of change in potential energy when m = 201kg of water is falling down a distance of h = 131m per second

$\dot{E_p} = \dot{m}gh = 201*9.81*131 = 258307 J/s (W) = 258.307 kW$

So the efficiency of the water turbine is the ratio of output power over input power:

$\frac{234}{258.307} = 0.906$

3 0

3 years ago

The ratio of the focal length of a lens to it's diameter is the

user100 [1]

Answer:

The f-ratio describes the relationship between the lens diameter and the focal length and is calculated by dividing the focal length by the diameter of the lens. For example, if a lens were to have a focal length of 50mm and a diameter of 10mm, then the f-ratio would be 50mm/10mm=5 or otherwise referred to as f5.

Explanation:

6 0

2 years ago

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