Shine the flashlight on the liquid crystal sheet. Did you observe evidence that light carries energy?

A stuffed toy with a mass of 0.900 kilograms sits on the edge of a bed at a height of 0.830 if the toy falls off the bed what wi

Olenka [21]

Mechanical energy (ME) is the sum of potential energy (PE) and kinetic energy (KE). When the toy falls, energy is converted from PE to KE, but by conservation of energy, ME (and therefore PE+KE) will remain the same.

Therefore, ME at 0.500 m is the same as ME at 0.830 m (the starting point). It's easier to calculate ME at the starting point because its just PE we need to worry about (but if we wanted to we could calculate the instantaneous PE and KE at 0.500 m too and add them to get the same answer).

At the start:

ME = PE = mgh
ME = 0.900 (9.8) (0.830)
ME = 7.32 J

8 0

2 years ago

Which does not describe the relationship between the nucleus and the electron cloud of an atom?

Margaret [11]

Choices 'a', 'c', and 'd' are true.

In choice 'b', I'm not sure what it means when it says that masses
are 'balanced'. To me, masses are only balanced when they're on
a see-saw, or on opposite ends of a rope that goes over a pulley.

Maybe the statement means that the mass of the nucleus and the
mass of the electron cloud are equal. This is way false. It takes
more than 1,800 electrons to make the mass of ONE proton or
neutron, and the most complex atom in nature only has 92 electrons
in it. So there's no way that the masses of the nucleus and the electrons
in one atom could ever be anywhere near equal.

4 0

2 years ago

Two moles of an ideal monatomic gas are at a temperature of 345 K. Then, 2250 J of heat is added to the gas, and 870 J of work i

Lapatulllka [165]

Answer: The final temperature is 470K

Explanation: Using the relation;

Q= ΔU +W

Given, n = 2mol

Initial temperature T1= 345K

Heat =Q= 2250J

Workdone=W=-870J(work is done on gas)

T2 =Final temperature =?

ΔU =3/2nR(T2-T1)

ΔU=3/2 × 2 ×8.314 (T2 - 345)

ΔU=24.942(T2-345)

Therefore Q = 24.942(T2-345)+ (-870)

2250=24.942(T2-345)+ (-870)

125.09=(T2-345)

T2 =470K

Therfore the final temperature is 470K

5 0

2 years ago

an object is acted on by a drag force with a magnitude that is proportional to the speed. the object accelerates downward at 3.0

Nutka1998 [239]

The terminal speed of the object falling down is 66.67 m/s.

The terminal speed acquired by the body when,

Weight of the body = Drag force of the body

It is given,

Drag force is directly proportional to the speed,

So,

F = CV

Where F is drag force,

V is the speed,

C is the constant,

So, it can be written as C = F/V.

The weight of the body = mg

The weight of the body = 10m

M is the mass and g is the acceleration due to gravity,

The drag force when the speed is 20m/s.

Drag force = ma

a is the acceleration during the drag force which is given to be 3m/s²,

Drag force = 3m

Now we can write,

F₁/V₁ = F₂/V₂

F₁ is the drag force at 20m/s speed.

F₂ is the weight of the body and V₂ is the terminal speed,

Now, it can be written,

3m/20 = 10m/V₂

V₂ = 66.67 m/s.

So, the terminal speed is 66.67m/s.

To know more about terminal speed, visit,

brainly.com/question/14605362

#SPJ4

7 0

11 months ago

A block of ice at 0°C is added to a 150g aluminum calorimeter cup which holds 210 g of water at 12°C. If all but 2.0 g of ice me

Over [174]

Answer:

original mass of the block of ice is 38.34 gram

Explanation:

Given data

cup mass = 150 g

ice temperature = 0°C

water mass = 210 g

water temperature = 12°C

ice melt = 2 gram

to find out

solution

we know here

specific heat of aluminum is c = 0.900 joule/gram °C

Specific heat of water C = 4.186 joule/gram °C

so here temperature difference is dt = 12- 0 = 12°C

so here heat lost by water and cup are given by

heat lost = cup mass × c × dt + water mass × C × dt

heat lost = 150 × 0.900 × 12 + 210 × 4.186 × 12

heat lost = 12168.72 J

so

mass of ice melt here = heat lost / latent heat of fusion

here we know latent heat of fusion = 334.88 joule/gram

so

mass of ice melt = 12168.72 / 334.88

mass of ice melt is 36.337554 gram

so mass of ice is here = mass of ice melt + ice melt

mass of ice = 36.337554 + 2

mass of ice = 38.337554 gram

so original mass of the block of ice is 38.34 gram

7 0

2 years ago