Ask question

Ask question

All categories

3 years ago

5

What does it mean to say the mass is conserved during a physical change ?

2 answers:

vesna_86 [32]3 years ago

5 0

The total mass of the substance remains the same from beginning to end. The physical properties of the substance, such as size and shape, may change. The amount of matter in the substance does not change.

Olin [163]3 years ago

4 0

Mater doesn't just appear or disappeared. Chemical elements are still there just the connections and how it combines changes.

So what goes into your chemical eqation must still exist after the change.

You might be interested in

Which of the following are true (choose all that apply)? Sound can travel through a vacuum. -Sound can travel through water. Lig

Lunna [17]

Answer:

option (A) - false

option (B) - true

option (C) - true

option (D) - true

option (E) - true

option (F) - true

Explanation:

The sound waves are mechanical waves that means they need a medium to travel.

The light waves are non mechanical waves it means they do not need a medium to travel.

Sound cannot travel trough vacuum.

Sound can travel through air and water.

Light can travel trough vacuum and in air and in water.

7 0

3 years ago

A student pushes on a 5 kg box with a force of 20 N forward. The force of sliding friction

mart [117]

Answer:

Explanation:

F=20N

mu=-10N

F=ma

20-10=10

10=(5)(a)

a=2 m/s^2

4 0

3 years ago

A ray of light strikes a plane mirror at an angle of incidence 35°. If the mirror is rotated through 10°.

xxTIMURxx [149]

Answer:

1 35°

2 20°

3 50°

..............

7 0

3 years ago

Which one should be my pfp?

Zepler [3.9K]

Explanation:

I think the third one coz it's so good

7 0

3 years ago

Read 2 more answers

A mass of 1000 kg drops from a height of 10 m on a platform of negligible mass. It is desired to design a spring and dashpot on

Juliette [100K]

Answer:

k = $5\times 10^{4}\ N/m$

b = $0.707\times 10^{3}$

t = $7.1\times 10^{- 5}\ s$

Solution:

As per the question:

Mass of the block, m = 1000 kg

Height, h = 10 m

Equilibrium position, x = 0.2 m

Now,

The velocity when the mass falls from a height of 10 m is given by the third eqn of motion:

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

where

u = initial velocity = 0

g = 10 $m/s^{2}$

Thus

$v = \sqrt{2\times 10\times 10} = 10\sqrt{2}\ m/s$

Force on the mass is given by:

F = mg = $1000\times 10 = 10000 N = 10\ kN$

Also, we know that the spring force is given by:

F = - kx

Thus

$k = \frac{F}{x} = \frac{10000}{0.2} = 5\times 10^{4}\ N/m$

Now, to find the damping constant b, we know that:

F = - bv

$b = \frac{F}{v} = \frac{10000}{10\sqrt{2}} = 0.707\times 10^{3}$

Now,

Time required for the platform to get settled to 1 mm or 0.001 m is given by:

$t = \frac{0.001}{v} = \frac{0.001}{10\sqrt{2}} = 7.1\times 10^{- 5}\ s$

4 0

3 years ago