PLEASE HELP EASY POINTS!!!!

Find the change in thermal energy of a 25kg severed clown doll head that heats up from 25°C to 35°C, and has the specific heat o

timama [110]

Answer:

Q = 425 kJ

Explanation:

Given that,

Mass, m = 25 kg

The clown doll head that heats up from 25°C to 35°C

The specific heat is 1700 J/kg°C

We need to find the internal energy of it. The heat required to raise the temperature is given by the formula as follows :

$Q=mc\Delta T\\\\Q=25\times 1700\times (35-25)\\\\Q=425000\ J\\\\Q=425\ kJ$

So, 425 kJ of thermal energy is severed.

6 0

3 years ago

the particles that make up a rock are constantly in motion however a rock does not visibly vibrate. why do you think this?

Ivahew [28]

I think this is because the particles don't know or care about each other,
and they act completely without any peer pressure. The direction in which
any one particle vibrates is completely random, and there is no connection
or influence among the particles. That means that any direction is just as likely
as any other direction for the next vibration, and they all wind up vibrating in
different directions. There is a tiny tiny tiny tiny chance that all of them could
vibrate in the same direction for just an instant; if that ever happened, the rock
would suddenly jump up in the air. That's actually true, but the chance is so tiny
that it hasn't ever happened yet. In fact, the chance is so tiny, that when scientists
do their calculations of particle vibrations, they assume that the chance is zero,
and that makes the calculations simpler.

3 0

3 years ago

To drive a typical car at 40 mph on a level road for one hour requires about 3.2 × 107 J of energy. Suppose we tried to store th

tatiyna

Answer:

9000RPM

Explanation:

"Angular velocity" is directly related to kinetic energy, that is, the Kinetic energy equation would allow an approximation to the resolution investigated in the problem.

The equation for KE is given by:

$KE = \frac{1}{2} lw ^ 2$

Now, starting from there towards the Angular equation of kinetic energy, the moment of inertia (i) is used instead of mass (m), and angular velocity (w) instead of linear velocity (V)

That's how we get

$KE_{Angular} = \frac{1}{2} Iw^2$

calculating the inertia for a solid cylindrical disk, of

m = 400kg

r = 1.2 / 2 = 0.6m

$I_{disk} = \frac{1}{2} mr^2 = (0.5) (400) (0.6)^2 = 72 kgm^2$

We understand that the total kinetic energy is 3.2 * 10 ^ 7J, like this:

$3.2*10^7 = \frac{1}{2} Iw^2 = (0.5) (72) w^2 = 36w^2$ $w^2 = 3.2*10^7 / 36 = 0.0888*10^7 = 88.8*10^4$

$w = 9.43*10^2 = 943 rad / s$

Thus,

943 rad / s ≈ 9000 rpm

6 0

3 years ago

An object is located 50 cm from a converging lens having a focal length of 15 cm. Which of the following is true regarding the i

Diano4ka-milaya [45]

Answer:

It is real, inverted, and smaller than the object.

Explanation:

First of all, we can use the lens equation to find the location of the image:

$\frac{1}{q}=\frac{1}{f}-\frac{1}{p}$

where

q is the distance of the image from the lens

f = 15 cm is the focal length (positive for a converging lens)

p = 50 cm is the distance of the object from the lens

Solving the equation for q,

$\frac{1}{q}=\frac{1}{15 cm}-\frac{1}{50 cm}=0.047 cm^{-1}\\q=\frac{1}{0.047 cm^{-1}}=21.3 cm$

The distance of the image from the lens is positive, so we can already conclude that the image is real.

Now we can also write the magnification equation:

${h_i}=-h_o \frac{q}{p}$

where $h_i, h_o$ are the size of the image and of the object, respectively.

Substituting p = 50 cm and q = 21.3 cm, we have

${h_i}=-h_o \frac{21.3 cm}{50 cm}=-0.43 h_o$

So from this relationship we observe that:

$|h_i| < |h_o|$ --> this means that the image is smaller than the object, and

$h_i < 0$ --> this means that the image is inverted

so, the correct answer is

It is real, inverted, and smaller than the object.

4 0

3 years ago

How does an inclined plane trade force for distance??

liq [111]

The sloping surface of the inclined plane supports part of the weight of the object as it moves up the slope. As a result, it takes less force to move the object uphill. The trade-off is that the object must be moved over a greater distance than if it were moved straight up to the higher elevation.

8 0

4 years ago