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3 years ago

Which would show an example of how physical changes are reversible?

Physics

2 answers:

Rina8888 [55]3 years ago

7 0

Answer:

melting tin and then cooling it into a mold

Explanation:

laiz [17]3 years ago

3 0

Examples of reversible changes include melting chocolate and changing it back into a solid by cooling it, and melting candle wax by heating it and solidifying the wax by cooling it. Reversible changes are changes that can be reversed. They are also known as physical changes.

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A person jumped off a cliff, what would happen?

Anastaziya [24]

Death would happen, hope this helped

8 0

2 years ago

Read 2 more answers

A 50kg chandelier hangs from a ceiling suspended by a cable.

babunello [35]

Answer:

The tension force has a magnitude of 490 N, and acts vertically upward

Explanation:

The complete question is:

A 50kg chandelier hangs from a ceiling suspended by a cable. What is the Tension (magnitude and direction of the force) in the cable?

ANS:

Tension is the force applied axially by rope, chain, cable, rod, etc, as a reaction force. The direction of tension is always towards the support. Since, the support here, is ceiling.

Therefore, the direction of tension force will be vertically upward.

Since the chandelier is hanging stationary, without any motion. Thus, there must not be any unbalanced force applied on it.

Hence, the tension force must be equal to the weight of chandelier.

Tension Force = Weight of Chandelier

T = W = mg

T = (50 kg)(9.8 m/s²)

T = 490 N

Thus, the tension force has a magnitude of 490 N, and acts vertically upward

6 0

3 years ago

Define weight Please help!!Thanks!!

Ksenya-84 [330]

Answer:

in science and engineering , the weight of an object is the force acting on the object due to gravity.

5 0

2 years ago

Car A with a mass of 725 kilograms is traveling east at an initial velocity of 15 meters/second. It collides head–on with car B,

shutvik [7]

Answer:

$p_t_o_t_a_l=250kg\frac{m}{s}$

Explanation:

The total momentum of a system is defined by:

$(mv)_t_o_t=m_1v_1+m_2v_2+...$

Where,

$(mv)_t_o_t$ is the total momentum or it could be expressed also as $p_t_o_t_a_l$ .

$m_1$ and $m_2$ represents the masses of the objects interacting in the system.

$v_1$ and $v_2$ are the velocities of the objects of the system.

Remember: The momentum is a fundamental physical magnitude of vector type.

We have:

$m_1=725 kg$

$v_1=15\frac{m}{s}\\m_2=625 kg$

We are going to take the east side as positive, and the west side as negative. Then the velocity of the car B, has to be negative. It goes in a different direction from car A.

$v_2=-17\frac{m}{s}$

Then the total momentum of the system is:

$p_t_o_t_a_l=m_1v_1+m_2v_2\\p_t_o_t_a_l=(725kg)(15\frac{m}{s})+(625kg)(-17\frac{m}{s})\\p_t_o_t_a_l=10875kg\frac{m}{s}-10625kg\frac{m}{s}\\p_t_o_t_a_l=250kg\frac{m}{s}$

5 0

3 years ago

the mass of the earth is 6×10²⁴ kg and the it's radius is 6400 km . what is the mass of a man weighing 977 N in spring balance ?

Anna71 [15]

Answer:

Mass of the man = 100 kg

Explanation:

Given that,

Mass of the Earth, M = 6×10²⁴ kg

The radius of the Earth, r = 6400 km

Force on man, F = 977 N

We need to find the mass of the man. Let the mass of the man be m. The gravitational force acting between two objects is given by :

$F=G\dfrac{mM}{r^2}\\\\m=\dfrac{Fr^2}{GM}\\\\m=\dfrac{977\times (6400\times 10^3)^2}{6.67\times 10^{-11}\times 6\times 10^{24}}\\\\m=99.99\ kg$

m = 100 kg

So, the mass of the man is 100 kg.

4 0

2 years ago