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2 years ago

1.) A(n) __________ change occurs when materials changes shape or size but the composition of the material does not change

Physics

1 answer:

olga_2 [115]2 years ago

6 0

a physical change occurs when materials change shape or size but not the molecular composition of the substance

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An 888.0 kg elevator is moving downward with a velocity of 0.800 m/s. It decelerates uniformly and comes to a stop in a distance

bagirrra123 [75]

Answer:

The value of tension on the cable T = 1065.6 N

Explanation:

Mass = 888 kg

Initial velocity ( u )= 0.8 $\frac{m}{sec}$

Final velocity ( V ) = 0

Distance traveled before come to rest = 0.2667 m

Now use third law of motion $V^{2}$ = $u^{2}$ - 2 a s

Put all the values in above formula we get,

⇒ 0 = $0.8^{2}$ - 2 × a ×0.2667

⇒ a = 1.2 $\frac{m}{sec^{2} }$

This is the deceleration of the box.

Tension in the cable is given by T = F = m × a

Put all the values in above formula we get,

T = 888 × 1.2

T = 1065.6 N

This is the value of tension on the cable.

5 0

3 years ago

The circuit has a 3 volt EMF and two ohm resistors. How much power in watts does this circuit draw? A) 4.5 , B) 24, C) 1.13 D) 2

dlinn [17]

Answer:

P = 4.5 watts

Explanation:

Given that,

EMF of the circuit, E = 3 volt

The resistance of the resistors, R = 2 ohms

We need to find the power of this circuit. The relation between power, emf and resistance is given by the formula as follows :

$P=\dfrac{V^2}{R}$

Substitute all the values,

$P=\dfrac{3^2}{2}\\\\P=4.5\ W$

So, the power of this circuit is equal to 4.5 watts.

5 0

2 years ago

9. A plane starts at rest & accelerates along the ground before takeoff. It

Phoenix [80]

Answer:

9.877 m/s^2

Explanation:

The acceleration can be computed from ...

d = (1/2)at^2

(1600 m) = (1/2)a(18 s)^2

a = (1600/162) m/s^2 ≈ 9.877 m/s^2

6 0

3 years ago

How many total oxygen atoms are in the compound Molybdenum (V) Dichromate?

alekssr [168]

Answer:

$1.2646\times10^{25}\ atoms$

Explanation:

-The chemical formula for Molybdenum (V) Dichromate is $Mo(Cr_2O_7)_3$

-There are 21 moles of oxygen per one mole of Molybdenum (V) Dichromate

-We apply Avogadro's constant to find the number of atoms of oxygen:

$Avogadro's \ Constant=6.022\times 10^{23} \ mol_1\\\\No\ of \ Atoms=Moles\times Avogadro's \ Constant\\\\=21\times 6.022\times 10^{23} \\\\=1.2646\times10^{25}\ atoms$

Hence, there are $1.2646\times10^{25} \ atoms$

3 0

3 years ago

2NaOH+H2SO4 Na2SO4+H2O the equation is balanced/unbalanced because the number of hydrogen atoms and oxygen/sodium is equal/not e

RUDIKE [14]

Your equation is:
$2NaOH + H_{2}SO_{4} ==\ \textgreater \ Na_{2}SO_{4} + H_{2}O$

An equation is balanced only if there are the same number of atoms of each element on both sides of the arrow - aka same number of atoms of each element in both reactants (left of the arrow) and products (right of the arrow).

It'll be easiest to tackle this by counting up the number of atoms of each element on the left and on the right and comparing those numbers. If there is a number in front of the entire compound, that means that number applies to all elements in the compound. If the number is a subscript (little number to the right of the element), that means that number only applies to the element that the subscript is attached to:
1) On the left, you have:
$2NaOH + H_{2}SO_{4}\\
\\
Na: \: 2 \: atoms\\
O: \: 2 + 4 = 6 \: atoms\\
H: \: 2 + 2 = 4 \: atoms\\
S: \: 1 \: atom$

2) On the right, you have:
$Na_{2}SO_{4} + H_{2}O\\
\\ 
Na: \: 2 \: atoms\\ 
O: \: 4 + 1 = 5 \: atoms\\ 
H: \: 2 \: atoms\\ 
S: \: 1 \: atom$

You can see that the number of oxygen and hydrogen atoms aren't equal on both the left (reactants) and the right (products), so the equation is unbalanced.

Your final answer is "T<span>he equation is unbalanced because the number of hydrogen atoms and oxygen is not equal in the reactants and in the products."</span>

5 0

2 years ago

Read 2 more answers