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goldfiish [28.3K]

3 years ago

6

All of the alkali metals, Group 1, have one valence electron. Which of these would represent the oxidation number of the alkali

metals such as lithium and sodium? A) -7 B) -1 C) +1 D) +7

1 answer:

Bond [772]3 years ago

6 0

The answer to this question is c

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What approximately is the percent uncertainty for the measurement 5.2

stiks02 [169]

I think is it 520% hope I helped

4 0

3 years ago

a skier speeds along a flat patch of snow, and then flies horizontally off the edge at 16.0 m/s. He eventually lands on a straig

geniusboy [140]

Answer:

1.63 s

Explanation:

The skier lands on the sloped section when the direction of its velocity is exactly identical to that of the slope, so at $45.0^{\circ}$ below the horizontal.

This occurs when the magnitude of the vertical velocity is equal to the horizontal velocity (in fact, $\tan \theta =\frac{|v_y|}{v_x}$ , and since $\theta=45.0^{\circ}, tan \theta = 1$ and so $|v_y| = v_x$ .

We already know the horizontal velocity of the skier:

$v_x = 16.0 m/s$

And this is constant during the entire motion.

The vertical velocity instead is given by

$v_y = u_y + gt$

where

$u_y = 0$ is the initial vertical velocity (zero since the skier flies off horizontally)

g = 9.8 m/s^2

t is the time

Here we have chosen the downward direction as positive direction.

Substituting $v_y = 16.0 m/s$ , we find the time:

$t=\frac{v_y}{g}=\frac{16.0}{9.8}=1.63 s$

5 0

3 years ago

A vertical scale on a spring balance reads from 0 to 250 N. The scale has a length of 15.0 cm from the 0 to 250 N reading. A fis

lesantik [10]

Answer:

Mass of fish=6.252 kg

Explanation:

Force F=0 N to 250 N

Length x=15.0 cm=0.15 m

Frequency f=2.60 Hz

To find

Mass of fish m

Solution

First we need to find spring constant

$k=Force/distance\\k=F/x\\k=250/0.15\\k=1666.7 N/m$

As we know that the time period is given as

$T=2\pi\sqrt{\frac{m}{k} }\\ And\\f_{Frequency} =1/T\\So\\1/f=2\pi\sqrt{\frac{m}{k} }\\1/f^{2}=4\pi^{2}\frac{m}{k}\\ k/f^{2}=4\pi^{2}m\\m=\frac{k}{4\pi^{2}f^{2} } \\m=\frac{1666.7}{4\pi^{2} (2.60)^{2} }\\ m=6.252kg$

4 0

3 years ago

Which ball has the greater acceleration at the instant of release

melisa1 [442]

I can't see either of them, so I must assume that they're both
far away from me, at different places in the solar system.

So I can say with some assurance that whichever ball is on the
more massive planet will have greater acceleration when it's dropped.
Its acceleration will be constant, from the instant of release until the
instant it hits the "ground" or whatever they call it on that planet.

3 0

3 years ago

A potential energy function for a system in which a two-dimensional force acts is of the form U = 3x6y − 5x. Find the force that

liq [111]

Answer:

Force, $F=((-18x^5y+5)i+(-3x^6)j)\ N$

Explanation:

Given that,

A potential energy function for a system in which a two-dimensional force acts is of the form of :

$U=3x^6y-5x$

We need to find the force that acts at the point (x, y). The force in 2 dimensional with components is given by :

$F=(\dfrac{-dU}{dx},\dfrac{-dU}{dy})\\\\F=(\dfrac{-d(3x^6y-5x)}{dx},\dfrac{d(3x^6y-5x)}{dy})\\\\F=(-(18x^5y-5)),(-(3x^6))\\\\F=((-18x^5y+5)i+(-3x^6)j)\ N$

So, the force acting at the point (x,y) is $((-18x^5y+5)i+(-3x^6)j)\ N$ . Hence, this is the required solution.

7 0

3 years ago