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3 years ago

A small 18 kilogram canoe is floating downriver at a speed of 1 m/s. What is the canoe's kinetic energy?

Physics

1 answer:

In-s [12.5K]3 years ago

8 0

Kinetic energy = (1/2) (mass) (speed²).

A Physicist in the canoe, or on a raft floating downriver next to the canoe, will say that the canoe's kinetic energy is zero.

A Physicist on the riverbank, watching the canoe drift by at 1 m/s, will say that its kinetic energy is 9 Joules.

They're both correct.

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Molecular orbital theory correctly predicts paramagnetism of oxygen gas. true or false

PtichkaEL [24]

Answer: Yes.

Explanation:

Oxygen has a bond order of two. The bond order of Oxygen molecule is calculated, where the [eight valence electrons in bonding molecular orbitals minus (-) four valence electrons in antibonding molecular orbitals]/2 in the electron configuration.

Atoms/molecules where electrons are paired are diamagnetic (repelled by both poles of a magnetic); while atoms/molecules that have one or more unpaired electrons are paramagnetic (attracted to magnetic field).

The two unpaired electrons of dioxygen molecules has made it paramagnetic. By pouring liquid oxygen between the poles of a strong magnet, the liquid stream will be contained by the filed and fills up the space between the poles.

3 0

3 years ago

You drop an ice cube into an insulated flask full of water and wait for the ice cube to completely melt. The ice cube initially

3241004551 [841]

Answer: $T=12.69^{\circ}C$

Explanation:

Given

Mass of ice $m=60 gm$

mass of water $M=760 gm$

Initial Temperature of water $T_i=20^{\circ}C$

Let T be the Final Temperature of mixture

Latent heat of Fusion $L=334 J/gm$

heat required to melt ice completely is

$Q_1=60\times 334=20.04 kJ$

Heat released by water is taken by ice thus

$Mc_{water}(20-T)=mL+mc_{water}(T-0)$

$0.76\times 4.184\cdot (20-T)=20.04+0.06\times 4.184\cdot (T)$

$T=12.69^{\circ}C$

7 0

3 years ago

What is the gravitational force between mars and Phobos

alina1380 [7]

Answer:

$F=5.16\times 10^{15}\ N$

Explanation:

We have,

Mass of Mars is, $m_M=6.42\times 10^{23}\ kg$

Mass of its moon Phobos, $m_P=1.06\times 10^{16}\ kg$

Distance between Mars and Phobos, d = 9378 km

It is required to find the gravitational force between Mars and Phobos. The force between two masses is given by

$F=G\dfrac{m_Mm_P}{d^2}$

Plugging all values, we get :

$F=6.67\times 10^{-11}\times \dfrac{6.42\times 10^{23}\times 1.06\times 10^{16}}{(9378\times 10^3)^2}\\\\F=5.16\times 10^{15}\ N$

So, the gravitational force is $5.16\times 10^{15}\ N$ .

8 0

3 years ago

In a parallel portion of a series-parallel circuit, the voltage across the branches can be found by multiplying the sum of the b

Julli [10]

Answer:

It's true.

Explanation:

It's true. When we connect two resistors in parallel the current is divided between the two in such a way that the sum of the currents on each resistor should be equal to the current on that branch. By finding the equivalent resistance we can use Ohm's law to determine the voltage drop across the resistors. This voltage drop is the same for both, since they're connected in parallel.

8 0

3 years ago

An autotransformer is used to reduce the voltage of a 100-kilovolt amp, 480-volt secondary of an isolated type transformer, to s

tigry1 [53]

Answer:

42KVA

Explanation:

Given data

High Voltage (HV)= 480V

Low Voltage (LV)= 277V

Fo find

Size of transformer=?

Solution

To find the size of transformer here we use the co-ratio.The Co-ratio is given as:

Co-Ratio= (HV - LV)/HV

where

HV is High Voltage

LV is Low Voltage

Now put the values we get

Co- Ratio=(480-277)/480=.42

So the size of transformer is 42KVA

5 0

3 years ago