True or false: Alcohol can cause an uncontrolled ________ of the eyes, making good vision almost impossible

g a small smetal sphere, carrying a net charge is held stationarry. what is the speed are 0.4 m apart

Veseljchak [2.6K]

Answer:

The speed of q₂ is $4\sqrt{10}\ m/s$

Explanation:

Given that,

Distance = 0.4 m apart

Suppose, A small metal sphere, carrying a net charge q₁ = −2μC, is held in a stationary position by insulating supports. A second small metal sphere, with a net charge of q₂ = −8μC and mass 1.50g, is projected toward q₁. When the two spheres are 0.800m apart, q₂ is moving toward q₁ with speed 20m/s.

We need to calculate the speed of q₂

Using conservation of energy

$E_{i}=E_{f}$

$\dfrac{1}{2}mv_{i}^2+\dfrac{kq_{1}q_{2}}{r_{i}}=\dfrac{kq_{1}q_{2}}{r_{f}}+\dfrac{1}{2}mv_{f}^2$

$\dfrac{1}{2}m(v_{i}^2-v_{f}^2)=kq_{1}q_{2}(\dfrac{1}{r_{f}}-\dfrac{1}{r_{i}})$

Put the value into the formula

$\dfrac{1}{2}\times1.5\times10^{-3}(20^2-v_{f}^2)=9\times10^{9}\times-2\times10^{-6}\times-8\times10^{-6}(\dfrac{1}{(0.4)}-\dfrac{1}{(0.8)})$

$0.00075(400-v_{f}^2)=0.18
$

$400-v_{f}^2=\dfrac{0.18}{0.00075}$

$-v_{f}^2=240-400$

$v_{f}^2=160$

$v_{f}=4\sqrt{10}\ m/s$

Hence, The speed of q₂ is $4\sqrt{10}\ m/s$

7 0

2 years ago

1.Which statement is true when two objects are 20 miles apart but one is much bigger?

Paha777 [63]

1. C. Gravitational attraction exists between the two objects.

Explanation:

Gravitational attraction is always exerted between two objects which have mass, and its magnitude is given by:

$F=G\frac{m_1 m_2}{r^2}$

where G is the gravitational constant, m1 and m2 the masses of the two objects, and r the separation between them. Since the two objects have for sure non-zero masses m1 and m2, even if they are 20 miles apart, the value of the gravitational attraction F is non-zero, so the correct answer is C.

2. D. Two atoms come together to form a molecule.

Explanation:

this outcome is actually caused by the electrostatic forces between the two atoms, not by gravitational force. In fact, gravitational force becomes relevant only when the masses of the two objects involved are large enough: this is the case for planets, stars, galaxies, and objects in the universe. However, two atoms have very small masses, so the gravitational force between them is really negligible. On this smaller scales, the electrostatic force is much stronger than the gravitational force, so the electrostatic force is the real responsible for the formation of bonds between atoms.

7 0

2 years ago

Read 2 more answers

Extreme-sports enthusiasts have been known to jump off the top of El Capitan, a sheer granite cliff of height 910 m in Yosemite

german

Answer:

The jumper is in freefall for 12.447 seconds.

Explanation:

Let's start by calculating how far the jumper falls.

Initial height (on cliff) = 910 m

Final height after freefall = 150 m

Distance the jumper falls in freefall = 910 - 150 = 760 m

We can now use the equation of motion below to solve for the time:

$s=u*t+\frac{1}{2} (a*t^2)$

here. acceleration = 9.81 m/s (due to gravity)

initial speed (u) = 0 m/s (because vertical speed is 0 at the start)

and distance (s) = 760 meters (as calculated above)

So for speed we get:

$760=0*t+0.5(9.81*t^2)$

$760=4.905t^2$

t = 12.447 seconds

5 0

3 years ago

Which of the following choices is a single-replacement reaction? A. 2K + Br2 2KBr B. 2H2 + O2 2H2O C. Mg + FeO Fe + MgO D. C + 2

Otrada [13]

A single replacement reaction occurs when two different cations switch places to combine with the same anion. One element forms a compound while another element is released from the compound. In a single replacement reaction, or single displacement reaction, a single<span> uncombined element replaces another in a compound.

So you're answer is probably c.
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5 0

2 years ago

A heat engine takes in 840 kJ per cycle from a heat reservoir. Which is not a possible value of the engine's heat output per cyc

zhannawk [14.2K]

We have by the first law of thermodynamics tha energy is preserved, hence we cannot have over 840kJ per cycle. We have by the laws of thermodynamics (the 2nd one in specific) that the entropy of a system cannot increase. We cannot have an output of 840 kJ per cycle from a heat engine because then that would mean that the entropy would stay the same, while any heat engine increases it. Hence, any value $\geq 840 kJ$ is acceptable.

8 0

2 years ago