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3 years ago

How long does it take to freeze ice cubes?

1 answer:

eduard3 years ago

4 0

<span>It actually depends on what water and what is in the water that you are freezing. Normal temperature water will freeze in about 3 to 4 hours, if you want it to really be hard, but it can already start freezing in about an hour. However, boiling water said to freeze faster.</span>

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A vertical spring has a length of 0.25 m when a 0.175 kg mass hangs from it, and a length of 0.775 m when a 2.075 kg mass hangs

Contact [7]

Answer:

A) 35.5N/m b) 20.1cm

Explanation:

Using Hooke's law;

F = Ke where F is the weight of the object = mass of the object in kg * acceleration due to gravity in m/s^2 and k if the force constant of the spring in N/m and e is the extension of the spring which original length of the spring - new length after extension in meters

For the first body, m*g = K * (0.25- li)

Where li is the initial length of the spring

0.175*9.81 = k(0.25-li)

1.72 = k(0.25-li) as equation 1

For the second body, m *g = K* ( 0.775-li)

2.075*9.81 = k (0.775-li) equation 2

20.36 = k(0.775-li)

Make li subject of the formula;

li = 0.775 - 20.36/k

Substitute for li in equation 1

1.72 = k(0.25- (0.775 - 20.36/k))

1.72 = k ( 0.25 - 0.775 + 20.36/k)

Open the bracket with k

1.72 = 0.25k - 0.775k + 20.36 (since k cancel k)

Collect the like terms:

1.72 - 20.36 = - 0.525k

- 18.64 = -0.525k

Divide both side by -0.525

-18.64/-0.525 = -0.525/-0.525k

K = 35.5N/m

B) substitute for k in using

li = 0.775 - 20.36/k

li = 0.775 - 20.36/35.5

li = 0.775 - 0.574

li = 0.201 in meters

li = 0.201 * 100 centimeters = 20.1cm

4 0

4 years ago

A playground merry-go-round spins about its axis with negligible friction. A child moves from the center of the merry-go-round t

Juli2301 [7.4K]

Answer:

Explanation:

In this process on merry go round there is not any external torque so angular momentum will be conserve. Mass is always conserved.

4 0

3 years ago

Tarzan, in one tree, sights Jane in another tree

taurus [48]

Taking the distance of Tarzan from the ground before and after he makes the swing:

Ho (initial height) = L(1 - cos45) = 20 (1 - 0.707) = 5.86 meters
Hf (final height) = L(1 - cos30) = 20 (1 - 0.866<span>) = 2.68 meters
</span>
Difference in height = 5.86 - 2.68 = 3.18 meters

PE = KE
mgh = (1/2)mv^2

Solving for v:
v = sqrt (2*g*h)
v = sqrt (2*9.8*3.18)
v = 7.89 m/s

With Tarzan going that fast, it is likely that he will knock Jane off.

8 0

3 years ago

Read 2 more answers

Suppose you need to design a parachute system to help a remote camera land safely

IgorLugansk [536]

The correct answer is hang glider.

A hang-glider cannot take off from low ground since it has no power. It needs to be launched from a high location, such a mountain or a hill. The major force acting on a hang-glider is gravity. The weight of the wing and the pilot together is this. The push that keeps the aerofoil flying through the air is produced by the weight. The hang-aerofoil glider's wing's form prevents it from falling to the ground like a stone. It results in lift. An area of low pressure is created by the aerofoil's acceleration of the air passing over the top of the wing. The air moving beneath the wing is compressed as the wing moves forward and downward. After then, the aerofoil is lifted up into the region of low pressure.

The air will gradually drop if it is still. A hang-glider descends at a speed of roughly 3.6 km/h (slow walking), or about 1 meter per second. A hang-glider needs to locate air coming up at the same rate as the glider is going down in order to maintain height. A hang-glider can fly along a cliff without losing height, for instance, if there is a light breeze coming straight from the sea, the air is being forced vertically upward by the cliff at 3.6 km/h, and the glider is flying over a vertical coastal cliff. The glider will begin to gain altitude in a stronger breeze.

Some hang-glider pilots equip their craft with tiny motors and propellers. They become microlights as a result and can now take off and climb from flat ground like a regular aircraft.

To learn more about hang-glider refer the link:

brainly.com/question/1365947

#SPJ9

4 0

1 year ago

ASK YOUR TEACHER A meter stick is found to balance at the 49.7-cm mark when placed on a fulcrum. When a 51.5-gram mass is attach

Simora [160]

Answer:

0.114 kg or 114 g

Explanation:

From the diagram attaches,

Taking the moment about the fulcrum,

sum of clockwise moment = sum of anticlockwise moment.

Wd = W'd'

Where W = weight of the mass, W' = weight of the meter rule, d = distance of the mass from the fulcrum, d' = distance of the meter rule.

make W' the subject of the equation

W' = Wd/d'................ Equation 1

Given: W = mg = 0.0515(9.8) = 0.5047 N, d = (39.2-16) = 23.2 cm, d' = (49.7-39.2) = 10.5 cm

Substitute these values into equation 1

W' = 0.5047(23.2)/10.5

W' = 1.115 N.

But,

m' = W'/g

m' = 1.115/9.8

m' = 0.114 kg

m' = 114 g

6 0

3 years ago