When you do glass blowing is it a chemical change or a physical change

notka56 [123]

Atoms are always neutral it means, the number of Protons & electrons are equal in them whereas ions are charged, the number is different depends on the kind of charge

Hope this helps!

3 0

3 years ago

Which term describes the amount of heat needed to change 1 kg of a substance from solid to liquid at its melting point? A. Speci

Lorico [155]

It is called the specific latent heat of fusion. C.

This is the heat change required in changing 1kg of a solid to its liquid and it occurs at the melting point. It is not associated with temperature change.

If it is to convert 1kg of liquid to vapor at its boiling point it is called the latent heat of vaporization.

6 0

3 years ago

The parking brake on a 1200kg automobile has broken, and the vehicle has reached a momentum of 7800kg.m/s. What is the velocity

liraira [26]

Answer:

Velocity of the vehicle (v) = 6.5 m/s

Explanation:

Mass of automobile (m) = 1200 kg

Momentum of vehicle (p) = 7800 kg m/s

By using formula of momentum:

$\rm p = mv \\ \rm 7800 = 1200 \times v \\ \rm v = \frac{7800}{1200} \\ \rm v = 6.5 \: m {s}^{ - 1}$

8 0

2 years ago

A traffic expert wants to estimate the maximum number of cars that can safely travel on a particular road at a given speed. He a

galben [10]

Answer:

Speed s= 19

Explanation:

Take note of the following parameters:

Speed= s,

Number of cars= N,

Number N of cars that can pass a given spot per minute=

N(s)=88s/16+16(s19)2

The principle of differentiation is here:

We let N(s) = N

N = 86s / (17 + 17((s/19)^2))

17N = 86s /(1 + s²/19²)

17N = 361* 86s /(361 + s²)

17N = 31046s /(361 + s²)

Next step;

Differentiate with respect to s

17N = 31046s /(361 + s²)

Remember the quotient rule [u/v]’ = (vu’ - uv’) / v²

Therefore,

u = 31046s =====> du/ds = u’ = 31046

v = (361 + s²) ====>dv/ds = v’ = 2s

17N = 31046s /(361 + s²)

17 dN/ds = ( 31046(361 + s²) - 31046s(2s) ) / (361 + s²)²

The maximum when dN/ds = 0

17 dN/ds = ( 31046(361 + s²) - 31046s(2s) ) / (361 + s²)²

17 * 0 = ( 31046(361 + s²) - 31046s(2s) ) / (361 + s²)²

( 31046(361 + s²) - 31046s(2s) ) = 0

31046 [ (361 + s²) - 2s² ] = 0

31046 (361 - s²) = 0

(361 - s²) = 0

(19 - s)(19 + s) = 0

either s = -19 or s = 19, but s > 0

s = 19

4 0

3 years ago

On his fishing trip Justin takes the boat 25 km south. The fish aren’t biting so he goes 10 km west. He follows a school of fish

S_A_V [24]

Distance is 50 km

Displacement is 10 km

Explanation:

Given:

Distance toward south, x = 25 km

Distance towards west, y = 10 km

Distance towards north, z = 15 km

(a) Total distance, D = ?

Total distance, D = x + y + z

D = 25 + 10 + 15

D = 50km

(b) Displacement, d = ?

Displacement = final position - initial position

= 10 - 0 km

= 10km

8 0

3 years ago