Ask question

Ask question

All categories

2 years ago

11

Which types of heat transfer involve heat flow from hot objects to colder objects? A. convection, conduction, and radiation B. c

onvection and radiation, but not conduction C. convection, but not conduction or radiation D. convection and conduction, but not radiation

2 answers:

bulgar [2K]2 years ago

6 0

its all 3 convection, radiation, and conduction

Soloha48 [4]2 years ago

4 0

B is definitely the answer. Please let it be

You might be interested in

A characteristic in an experiment, such as how much food, how much space, how hot or how cold, is termed a ____________. (spelli

KATRIN_1 [288]

I think the term is a variable?

6 0

2 years ago

Read 2 more answers

A scientist wants to model an internal organ with connective tissue as a mass on a spring. The mass of the organ is 2.0 kg, and

vichka [17]

Answer:

Spring constant, k = 5483.11 N/m

Explanation:

It is given that,

Mass of the organ, m = 2 kg

The natural period of oscillation is, T = 0.12 s

Let k is the spring constant for the spring in the scientist's model. The period of oscillation is given by :

$T=2\pi\sqrt{\dfrac{m}{k}}$

$k=\dfrac{4\pi^2 m}{T^2}$

$k=\dfrac{4\pi^2 \times 2\ kg}{(0.12\ s)^2}$

k = 5483.11 N/m

So, the spring constant for the spring in the scientist's model is 5483.11 N/m.

5 0

3 years ago

The acceleration due to gravity vector is always in the ____ direction.

finlep [7]

It goes in the downward direction

4 0

2 years ago

An Olympic swimmer swims 50.0 meters in 23.1 seconds . What is his average speed

Aneli [31]

If you take 50 meters and divide by 23.1 seconds, you will get 2.16 meters per second.

So his average speed is 2.16 m/s.

3 0

2 years ago

Consider a father pushing a child on a playground merry-go-round. The system has a moment of inertia of 84.4 kg.m^2. The father

Sophie [7]

Answer:

Explanation:

Given that:

the initial angular velocity $\omega_o = 0$

angular acceleration $\alpha$ = 4.44 rad/s²

Using the formula:

$\omega = \omega_o+ \alpha t$

Making t the subject of the formula:

$t= \dfrac{\omega- \omega_o}{ \alpha }$

where;

$\omega = 1.53 \ rad/s^2$

∴

$t= \dfrac{1.53-0}{4.44 }$

t = 0.345 s

b)

Using the formula:

$\omega ^2 = \omega _o^2 + 2 \alpha \theta$

here;

$\theta$ = angular displacement

∴

$\theta = \dfrac{\omega^2 - \omega_o^2}{2 \alpha }$

$\theta = \dfrac{(1.53)^2 -0^2}{2 (4.44) }$

$\theta =0.264 \ rad$

Recall that:

2π rad = 1 revolution

Then;

0.264 rad = (x) revolution

$x = \dfrac{0.264 \times 1}{2 \pi}$

x = 0.042 revolutions

c)

Here; force = 270 N

radius = 1.20 m

The torque = F * r

$\tau = 270 \times 1.20 \\ \\ \tau = 324 \ Nm$

However;

From the moment of inertia;

$Torque( \tau) = I \alpha \\ \\ Since( I \alpha) = 324 \ Nm. \\ \\ Then; \\ \\ \alpha= \dfrac{324}{I}$

given that;

I = 84.4 kg.m²

$\alpha= \dfrac{324}{84.4} \\ \\ \alpha=3.84 \ rad/s^2$

For re-tardation; $\alpha=-3.84 \ rad/s^2$

Using the equation

$t= \dfrac{\omega- \omega_o}{ \alpha }$

$t= \dfrac{0-1.53}{ -3.84 }$

$t= \dfrac{1.53}{ 3.84 }$

t = 0.398s

The required time it takes= 0.398s

5 0

2 years ago