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3 years ago

13

I have a doubt on heat and temperature. I need help with this science question and here the question: The water in a lake just r

eached freezing point temperature. Why can’t you go ice skating on it yet?

1 answer:

Volgvan3 years ago

5 0

Answer:

you can't go ice skating on it because if it just reached the temp then you need to wait for about 2 hours

Explanation:

You might be interested in

An object of mass m is hung from a spring and set into oscillation. The period of the oscillation is measured and recorded as T.

sergejj [24]

Answer: $\sqrt{2}T$

Explanation:

Given

object of mass m is suspended from spring and set in oscillation with time Period T

We know Time period of a mass in oscillation is given by

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

where k=spring constant

When mass m is replaced by a mass of 2 m time period is given by

$T'=2\pi \sqrt{\frac{2m}{k}}$

$T'=\sqrt{2}\times 2\pi \sqrt{\frac{m}{k}}$

$T'=\sqrt{2}T$

i.e. New time period becomes $\sqrt{2}$ times of previous one

7 0

3 years ago

650 N boy and a 419 N girl sit on a 150 N porch swing that is 2.0 m long. If the swing is supported by a chain at each end, what

Sergio039 [100]

The tension in the two chains T1 and T2 is 676.65 N and 542.53 N respectively.

<h3>Principle of moments</h3>

The Principle of Moments states that when a body is in equip, the sum of clockwise moment about a point is equal to the sum of anticlockwise moment about the same point.

The formula for calculating moment is given below:

Moment = Force × perpendicular distance from the pivot

<h3>Calculating the tension in the chains</h3>

From the principle of moments:

Let tension in chain 1 be T1 and tension in chain 2 be T2.

T1 + T2 = 150 + 650 + 419

T1 + T2 =1219

Taking all distances from chain 1,

Sum of Moments = 0

419 × 0.5 + 150 × 0.85 + 650 × 0.9 = T2 × 1.7

T2 = 922/17

T2 = 542.35 N

Then, T1 = 1219 - 542.35

T1 = 676.65 N

Therefore, the tension in the two chains T1 and T2 is 676.65 N and 542.53 N respectively.

Learn more about tension and moments at: brainly.com/question/187404

brainly.com/question/14303536

7 0

2 years ago

Un avión de rescate en Alaska deja caer un paquete de provisiones a un grupo de exploradores extraviados. Si el avión viaja hori

posledela

Answer:

180.4 m

Explanation:

The package in relation to the point where it was released falls a certain distance that is calculated by applying the horizontal motion formulas , as the horizontal speed of the plane and the height above the ground are known, the time that It takes the package to reach its destination and then the horizontal distance (x) is calculated from where it was dropped, as follows:

$V_{ox}=v_x = 40 \ m/s$

h = 100 m

x =?

Height formula h:

$h=g \times \frac{t^2}{2}$

Time t is cleared:

$t = \sqrt{\frac{2h}{g}}$

$t = \sqrt{\frac{2 \times 100}{9.8}}$

t = 4.51 sec

Horizontal distance formula x:

$x=V_x \times t$

x = 40 m / sec x 4.51 sec

x = 180.4 m

4 0

3 years ago

A 650-kg elevator starts from rest. It moves upward for 3.00 s with constant acceleration until it reaches its cruis- ing speed

Nataly_w [17]

Answer: $P=5573.43\ W$

Explanation:

Given

Mass of the elevator is $M=650\ kg\\\$

Time period of ascension $t=3\ s$

cruising speed $v=1.75\ m/s$

Distance moved by elevator during this time

Suppose Elevator starts from rest

$\Rightarrow v=u+at\\\Rightarrow 1.75=0+a(3)\\\Rightarrow a=0.583\ s$

Distance moved

$\Rightarrow h=ut+0.5at^2\\\Rightarrow h=0+0.5\times 0.5833\times (3)^2\\\Rightarrow h=2.62\ m$

Gain in Potential Energy is

$\Rightarrow E=mgh\\\Rightarrow E=650\times 9.8\times 2.62\\\Rightarrow E=16,720.3\ N$

Average power during this period is

$\Rightarrow P=\dfrac{E}{t}\\\\\Rightarrow P=\dfrac{16,720.3}{3}\\\\\Rightarrow P=5573.43\ W$

7 0

3 years ago

Read 2 more answers

The circuit below contains an ideal battery, four identical light bulbs, and a switch. The switch is initially open.

Dafna1 [17]

The question is incomplete! circuit figure is attached below and answer and explanation is provided below.

Answer:

Bulb_A = Bulb_B = Bulb_D and Bulb_C = 0.

Explanation:

What happens when switch is open?

When the switch is open Bulb_C is open circuited meaning that there is no way for the current to flow through it. This path offers infinite resistance to the current therefore, current will try to take a least resistance path that is through Bulb_B.

So eventually, when the switch is open the circuit becomes a simple series circuit with path From battery to Bulb_A to Bulb_B to Bulb_D to battery with Bulb_C = 0.

What happens in a series circuit?

We know that in a series circuit, there is only one path for the current to flow therefore, same current will flow through all the series Bulbs and their brightness will be same. Bulb_A = Bulb_B = Bulb_D

Brightness in a series circuit:

We also know know that in a series circuit, resistance gets summed up and voltage across each Bulb gets shared which results in less power dissipation that's why Bulbs connected in series appear dimmer as compared to when they are connected in parallel.

5 0

3 years ago