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3 years ago

When water in a lake freezes, the ice that forms floats on top of any water that is still liquid. Why does the ice float?

Physics

1 answer:

ddd [48]3 years ago

5 0

Answer:

it floats because the lake is cold at that moment so when part of the lake freezes it still remains solid and floats because of the lake and the surrounding of the lake is still cold

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A candy-filled piñata is hung from a tree for Matthew's birthday. During an unsuccessful attempt to break the 4.4-kg piñata, Hay

Margaret [11]

Answer:

The speed of the piñata immediately after being cracked by the stick is $v_{fp}=0.59\: m/s$ .

Explanation:

Using the conservation of linear momentum:

$m_{s}v_{is}=m_{p}v_{fp}$ (1)

Here:

m(s) is the mass of the stick

m(p) is the mass of the piñata

v(is) is the initial velocity of the stick

v(fp) is the final velocity of the piñata

So, we just need to solve the equation (1) to v(fp).

$v_{fp}=\frac{m_{s}v_{is}}{m_{p}}$

$v_{fp}=\frac{0.54*4.8}{4.4}$

$v_{fp}=0.59\: m/s$

I hope it helps you!

8 0

2 years ago

Write the minkowski version of newtons seconds law in terms of proper acceleration

Sindrei [870]

F=ma where f=force,m=mass,acceleration =a

4 0

3 years ago

What is emotional strength?

Ugo [173]

Answer:

Emotional strength is a person's ability to deal with challenges (any kind) and how they can bounce back on that certain situation.

I hope this helps you.

4 0

3 years ago

A bird watcher meanders through the woods, walking 1.93 km due east, 1.03 km due south, and 3.84 km in a direction 52.8 ° north

Sedaia [141]

Answer:

Magnitude of displacement = 2.07 km

Magnitude of average velocity = 1.17 kmph

Explanation:

Let east represent positive x axis and north represent positive y axis.

A bird watcher meanders through the woods, walking 1.93 km due east, 1.03 km due south, and 3.84 km in a direction 52.8 ° north of west.

1.93 km due wast

s ₁ = 1.93 i km

1.03 km due south

s₂ = -1.03 j km

3.84 km in a direction 52.8 ° north of west

s₃ = -3.84 cos 52.8 i + 3.84 sin 52.8 j = -2.32 i + 3.06 j km

Total displacement

s = s ₁+ s₂+ s₃ = 1.93 i - 1.03 j -2.32 i + 3.06 j = -0.39 i + 2.03 j

Magnitude of displacement, $=\sqrt{(-0.39)^2+2.03^2}=2.07km$

Time taken = 1.771 hour

Magnitude of average velocity, $=\frac{2.07}{1.771}=1.17km/hr$

7 0

3 years ago

A 1kg ball is dropped (from rest) 100m onto a spring with spring constant 125N/m. How much does the spring compress?

Anastasy [175]

Answer:

3.95 m

Explanation:

m = 1 kg, h = 100 m, k = 125 N/m

Let the spring is compressed by y.

Use the conservation of energy

potential energy of the mass is equal to the energy stored in the spring

m x g x h = 1/2 x ky^2

1 x 9.8 x 100 = 0.5 x 125 x y^2

y^2 = 15.68

y = 3.95 m

7 0

3 years ago