All categories

3 years ago

HHHHHEEEELLLPP

Physics

2 answers:

Nina [5.8K]3 years ago

8 0

I believe the correct answer is a.) conduction <span />

AleksandrR [38]3 years ago

8 0

Here is your answer:

Your answer is A conduction.

Reason: Conductions is when for example boiling water you put a metal spoon in the boiling water within seconds the spoon is hot that's because the heat from the boiling water transfered into the spoon making it hot! Also its not convection because it can't no be transfered between a solid an in the questions it has the word "solid" its also not D because that's when something or someone is under a lot of heat making them hot within minutes and when it came down to rather conduction and insulation I choose conduction because insulation is used for medicines!

Your answer is A.

You might be interested in

g A solid disk rotates in the horizontal plane at an angular velocity of rad/s with respect to an axis perpendicular to the disk

maksim [4K]

Complete question:

A solid disk rotates in the horizontal plane at an angular velocity of 0.067 rad/s with respect to an axis perpendicular to the disk at its center. The moment of inertia of the disk is 0.18 kg.m2. From above, sand is dropped straight down onto this rotating disk, so that a thin uniform ring of sand is formed at a distance of 0.40 m from the axis. The sand in the ring has a mass of 0.50 kg. After all the sand is in place, what is the angular velocity of the disk?

Answer:

The angular velocity of the disk is 0.0464 rad/s

Explanation:

Given;

initial angular velocity of disk, ωi = 0.067 rad/s

initial moment of inertia of the disk, I₁ = 0.18 kg.m²

radius of sand on the disk, R = 0.40 m

mass of sand, m = 0.50 kg

Initial angular momentum = Final angular momentum

$I_i \omega_i = I_f \omega_f\\\\I_i \omega_i = (I_{sand} + I_{disk})\omega _f$

Moment of inertia of sand ring = MR²

$\omega_f = \frac{I_i\omega_i}{I_{sand} +I_{disk}} = \frac{0.18*0.067}{MR^2 +0.18} \\\\\omega_f = \frac{0.18*0.067}{0.5*0.4^2 +0.18}= 0.0464 \ rad/s$

Therefore, the angular velocity of the disk is 0.0464 rad/s

8 0

3 years ago

A large cube (mass = 25 kg) being accelerated across a horizontal frictionless surface by a horizontal force . A small cube mass

belka [17]

Answer:F=400.28 N

Explanation:

Given

mass of large cube $M=25 kg$

mass of small cube $m=4 kg$

coefficient of static friction $\mu =0.71$

acceleration a of the system is given by

$F=(M+m)a$

$a=\frac{F}{M+m}$

Now Normal reaction between two blocks is given by

$N=ma$

friction tries to balance weight

thus $f_r=mg$

and $f_r=\mu N$

$f_r=\mu ma$

$\mu ma=mg$

$\mu \frac{F}{M+m}=g$

$F=\frac{(M+m)g}{\mu }$

$F=\frac{29\times 9.8}{0.71}$

$F=400.28 N$

7 0

3 years ago

energy is conserved. that is, it can never be created or destroyed. however, every time a conservation of energy occurs, some is

gladu [14]

Answer:

D. heat

Explanation:

7 0

4 years ago

Read 2 more answers

On the basis, a given figure, calculate rfficiency of the lever.

daser333 [38]

Explanation:

here,load=100N

effort=200N

distance travelled by load=2cm

distance travelled by effort=10cm

Now, output work=L*Ld

=100*2

=200g

Again,

input work =E*Ed

200*10

2000j

again, efficiency = output work/input work*100%

200/2000*100%

=10%

please don't forget to write symbol

4 0

3 years ago

A girl is sitting in a sled sliding horizontally along some snow (there is friction present).

Over [174]

Answer:

159 N

Explanation:

The force of friction, Fr is a product of coefficient of feiction and the normal force. Therefore, Fr=uN where N is the normal force and u is coefficient of friction. Here, we have two coefficients of friction but since it is sliding, then we use coefficient of kinetic energy. Substituting 0.25 for u and 636 N for N then

Fr=0.25*636=159 N

Therefore, the force of friction is equivalent to 159 N

4 0

3 years ago