Metals are good conductors because the molecules that are inside the metal are tightly packed together. This is why the heat moves through the metal quickly.

6 0

3 years ago

a concrete slab 20 m long and weighing 400,000 N is supported by one pillar. A 19,600 N car is parked 8 meters from one end, whe

Elden [556K]

let the distance of pillar is "r" from one end of the slab

So here net torque must be balance with respect to pillar to be in balanced state

So here we will have

$Mg(r - L/2) = mg(L/2 - 8)$

here we know that

mg = 19600 N

Mg = 400,000 N

L = 20 m

from above equation we have

$400,000(r - 10) = 19,600 (10 - 8)$

$r - 10 = 0.098$

$r = 10.098 m$

so pillar is at distance 10.098 m from one end of the slab

3 0

3 years ago

What is not an example of absorption ?

blsea [12.9K]

-- water shooting out of a hose

-- writing an email

-- making hard-boiled eggs

-- driving to the dentist

-- the emission spectrum of a carbon arc

-- buying a new car

-- putting your shoes on

-- singing a song

-- cutting a tree down

-- learning to dance

-- cleaning the windows

-- building a radio

-- ironing your shirt

-- riding a bicycle

-- playing the piano

3 0

3 years ago

HURRY!!!!

VMariaS [17]

Answer:

Ted is correct

Explanation:

The equation for gravitational potential energy is PE = m·g·h

The equation for gravitational kinetic energy is KE = 1/2·m·v²

Where:

m = Mass of the object (The racing car)

g = Acceleration due to gravity

h = The height to which the object is raised

v = Velocity of motion of the object

From the principle of conservation of energy, energy can neither be created nor destroyed but changes from one form to another, we have;

Potential energy gained from location at height h = Kinetic energy gained as the object moves down the level ground

m·g·h = 1/2·m·v² canceling like terms gives

g·h = 1/2·v²

v = (√2·g·h)

If the speed is doubled, we have

2·v = 2× (√2·g·h) = (√2·g·4·h)

Therefore, if 2·v = v₂ then v₂ = (√2·g·4·h)

Since g, the acceleration due to gravity, is constant, it means that the initial height must be multiplied or increased 4 times to get the new height, that is we have;

v₂ = (√2·g·4·h) = (√2·g·h₂)

Where:

4·h = h₂

Which gives;

v₂² = 2·g·h₂

1/2·v₂² = g·h₂

1/2·m·v₂² = m·g·h₂ Just like in the first relation

Therefore, Ted is correct s they need to go up four times the initial height to double the speed.

5 0

3 years ago