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2 years ago

Help I don’t understand this question

Physics

1 answer:

7nadin3 [17]2 years ago

5 0

Metals
3/4 of the periodic table
Good conductors of heat and electricity
Malleable

Nonmetals
1/4 of the periodic table
Bad conductors of heat and electricity
Not bendable

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When are the two days of equinox

galina1969 [7]

March 20 and September 22

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3 years ago

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when a tuning fork vibrates over an open pipe and the air in the pipe starts to vibrate, the vibrations in the tube are caused b

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Sound waves....................................

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3 years ago

how much gravitational potential energy do you give a 70 kg person when you lift him up 3 m in the air?

SCORPION-xisa [38]

Given gravitational potential energy when he's lifted is 2058 J.

Kinetic energy is transferred to the person.

Amount of kinetic energy the person has is -2058 J

velocity of person = 7.67 m/s².

<h3>Explanation:</h3>

Given:

Weight of person = 70 kg

Lifted height = 3 m

1. Gravitational potential energy of a lifted person is equal to the work done.

$PE_g=W=m\times g\times h\\Acceleration due to gravity = g = 9.8 \ m/s^2 \\PE_g= m = m\times g\times h= 70\times 9.8 \times 3 = 2058\ kg.m/s^2 = 2058\ J$

Gravitational potential energy is equal to 2058 Joules.

2. The Gravitational potential energy is converted into kinetic energy. Kinetic energy is being transferred to the person.

3. Kinetic energy gained = Potential energy lost = $-PE_g = -2058\ kg.m/s^2$

Kinetic energy gained by the person = (-2058 kg.m/s²)

4. Velocity = ?

Kinetic energy magnitude= $\frac{1}{2} m\times v^2 = m\times g \times h$

Solving for v, we get

$v=\sqrt{2gh} =\sqrt{2\times 9.8 \times 3} = \sqrt{58.8} = 7.67 m/s^2$

The person will be going at a speed of 7.67 m/s².

4 0

3 years ago

You calculate the density of a block of aluminum to be 2.68 g/cm3. You look up the density of a block of aluminum at room temper

Hunter-Best [27]

Answer:

Systematic errors.

Explanation:

The density of the aluminium was calculated by a human and this is not natural but can be due to errors in the calibration of the scale for measuring the weight or taking readings from the measuring cylinder.

Random errors are natural errors. Random errors in experimental measurements are caused by unknown and unpredictable changes in the experiment. Systematic errors are due to imprecision or problems with instruments.

3 0

3 years ago

A person carries a plank of wood 2.00 m long with one hand pushing down on it at one end with a force f1 and the other hand hold

slega [8]

Answer:

F₁ = 4,120.2 N

F₂ = 3,924N

Explanation:

1) Balance of angular momentum around the end where F₁ is applied.

F₂ × 0.5m - F₁ × 0 = mass × g × 1m

⇒ F2 × 0.5 m= 20 kg × 9.81 m/s² × 1 m = 1,962 N×m

F₂ = 196.2 Nm / 0.5m = 3,924 N

2) Balance of forces

F₁ - F₂ = mg

F₁ = F₂ + mg = 3,924N + 20kg (9.81 m/s²) = 4,120.2 N

4 0

3 years ago