If al snow and glaiers melted, would the sea level rise or fall

Football helmets are made with padding that helps reduce head injuries when a player collides with an object. Which bestexplains

Vlad1618 [11]

football hemets have pads that are filled with air and thick foam so when they are hit the foam asorbs the hit and the air keeps the hard outer shell of the helmet from hiting the players head

3 0

3 years ago

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A gas undergoes two processes. In the first, the volume remains constant at 0.200 m3 and the pressure increases from 1.00×105 Pa

Alborosie

Explanation:

In the first case , the volume is kept constant and pressure varies .

In isothermal process , the work done

W₁ = V x ΔP

here V is the volume of gas and ΔP is the change in pressure

Thus W₁ = 0

Because there is no change in volume , therefore displacement is zero .

In second case pressure is constant , but volume changes

Thus W₂ = P x ΔV

here P is the pressure and ΔV is the change in volume

Therefore W₂ = 4 x 10⁵ x 5 x 10⁻² = 2 x 10⁴ J

The total work done W = - 2 x 10⁴ J

Because the work done in compression is negative .

7 0

3 years ago

A stone is thrown vertically upwards with an initial velocity of 20m/sec. Find the maximum height ot reaches and the time taken

MAXImum [283]

Answer:

The height reached is 20m, The time taken to reach 20m is 2 seconds

Explanation:

Observing the equations of motion we can see that the following equation will be most helpful for this question.

$v^{2} = u^{2} + 2as$

We are given initial velocity, u

We know that the stone will stop at its maximum height, so final velocity, v

Acceleration, a

And we are looking for the displacement (height reached), s

Substitute the values we are given into the equation

$0^{2} = 20^{2} + 2(10)s$

Rearrange for s

$0^{2} -20^{2} =20s$

$-400=20s$

$\frac{-400}{20} =s$

s = -20 (The negative is just showing direction, it can be ignored for now)

The height reached is 20m

Use a different equation to find the time taken

$s = vt - \frac{1}{2} at^{2}$

Substitute in the values we have

$-20=(0)t - \frac{1}{2} (10)t^{2}$

Rearrange for t

$-20 =0 -5 t^{2}$

$\frac{-20}{-5} =t^{2}$

$4 = t^{2}$

t = 2s

The time taken to reach 20m is 2 seconds

4 0

3 years ago

What does it mean to say that science is a “systematic” process?

Maurinko [17]

Systematic is just a certain way of doing something. So science being systematic may just refer to the scientific method or how theories are proved in science by repeating the scientific method over and over again.

5 0

3 years ago

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A boat, whose speed in still water is 2.50 m/s, must cross a 285-m wide river and arrive at a point 118m upstream from where it

son4ous [18]

The figure shows the arrangement of system

The velocity of boat can be resolved in to two

Horizontal component = vcos θ = 2.50 cos 45 = 1.768 m/s

Vertical component = vsin θ = 2.50 sin 45 = 1.768 m/s

Due to horizontal component the boat arrive arrives upstream,

Total horizontal velocity = 1.768 - Vr, where Vr is the velocity of river.

Total time taken to cross the river = width of river/ Vertical component of velocity

t = 285/1.768 = 161.20 seconds

So 118 meter is traveled at a velocity of 1.768-Vr in 161.20 seconds

That is 118 = (1.768-Vr)*161.20

1.768 - Vr =0.732

Vr = 1.036 m/s

So velocity of river flow =1.036 m/s

4 0

3 years ago