The standard unit of brightness is called the candela. True False

The following reaction is balanced: N2 + 3H2 → 2NH3 True or False?

vivado [14]

Yes it is.

N₂ + 3H₂ ⇒ 2NH₃

5 0

3 years ago

To sterilize a 48.0-g glass baby bottle, we must raise its temperature from 16.0°C to 94.0°C. How much heat transfer is required

FinnZ [79.3K]

Answer:

3144.96 J

Explanation:

Heat transfer is,

$q=mc\Delta t$

As we know that the specific heat of the glass is,

$c=0.840J/g^{\circ}C$

Given that the mass of bottle is 48 g.

And the initial temperature is 16°C and the final temperature is 94°C.

Therefore,

$q=48\times 0.840(94^{\circ}-16^{\circ})\\q=48\times 0.840\times 78^{\circ}\\q=3144.96 J$

7 0

3 years ago

You are standing on a bathroom scale in an elevator in a tall building. Your mass is

Oksanka [162]

Answer:

94 kg or 921.6 N

Explanation:

The velocity function is $v(t) = 3t + 0.2t^2$ . The acceleration function, a(t), is the time derivative of the velocity function.

$a(t) = \dfrac{d}{dt}v(t) = 3 + 0.4t$

At $t=4$ ,

$a(4) = 3 + 0.4\times4 = 3+1.6 =4.6\text{ m/s}{}^2$

Because the elevator is going upwards, the net acceleration, $a_N = g + a(4)$ where g us acceleration of gravity.

$a_N = 9.8 + 4.6 = 14.4\text{ m/s}{}^2$

The resultant weight is

$W =m a_N =64\times14.4=921.6 \text{ N}$

Since the bathroom scale is graduated in kg, it's reading is

$m =\dfrac{W}{g}=\dfrac{921.6}{9.8}=94\text{ kg}$

3 0

3 years ago

Which of these instruments is listed with the wrong type of lens that it uses?

VikaD [51]

The wrong type of lens-Microscope, concave

Explanation:

A microscope Basically uses two convex lenses to magnify an object, or specimen.

There are 2 lenses in a microscope

Object Lens:The lens that is closer to the object
Eyepiece:The lens that is closer to the eye

Both the object lens and the eyepiece, is a convex lens.

3 0

3 years ago

You push very hard on a heavy desk, trying to move it. You do work on the desk:

frozen [14]

Answer:

(C) Only if it starts moving

Explanation:

We know that work done is given by

$W=F.d=Fdcos\Theta$

So there are two case in which work done is zero

First case is that when force and displacement are perpendicular to each other

And other case is that when there is no displacement

So for work to be done there must have displacement, if there is no displacement then there is no work done

So option (c) will be the correct option

3 0

3 years ago