A boy jumps from a wall 3m high. What is an estimate of the change in momentum of the boy when he lands without rebounding?

A drag racer starts from rest and accelerates at 10 m/s squared for the

nika2105 [10]

Answer:

54 $\frac{m}{s}$

Explanation:

$v=u+at$

where $u=$ initial velocity

$v=0+(10\frac{m}{s^{2} } )$ × $(5.4s)$

$v=54\frac{m}{s}$

6 0

3 years ago

What is special relativity

Rudiy27

Answer:

In physics, special relativity (also known as the special theory of relativity) is the generally accepted and experimentally confirmed physical theory regarding the relationship between space and time.

We need special relativity in order to solve for quantum gravity. ... The earth was expanding (thus, it's mass was expanding) through space in all directions in order to create gravity **OOPS** forgot, specifically at an accelerating rate… OR… The space must be pushing toward or down on the earth, from every direction.

4 0

3 years ago

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A 2.4-m high 200-m2 house is maintained at 22Â°C by an air-conditioning system whose COP, is 3.2. It is estimated that the kitch

kotegsom [21]

Answer:

The amount that is "vented" out by "the fans" is <u>$0.50</u> for 10 hours.

Option: a

<u>Explanation</u>:

"Energy discharged by air in every hour" can be determined by,

$\mathrm{Q}=\mathrm{m}_{\mathrm{air}} \mathrm{C}_{\mathrm{p}} \Delta \mathrm{T}$

Q = heat energy (Joules, J)

m = mass of a substance (kg)

c = specific heat (units J/kg∙K)

$\mathrm{m}_{\mathrm{air}}=\rho \mathrm{v}$

$\text { Density of air } \rho=1.20 \mathrm{kg} / \mathrm{m}^{3}$

$\text { Density of air } \rho=1.20 \times 200 \times 2.4$

$\text { Density of air } \rho=576 \mathrm{kg}$

∆T = 10 hours

$\text { Specific Heat Capacities of Air. The nominal values used for air at } 300 \mathrm{K} \text { are } \mathrm{C_P}=1.00 \mathrm{kJ} / \mathrm{kg} . \mathrm{K}$

Q = 576 × 1.00 × 10

Q = 5760 kJ/hours

W = 1.6 kwh

We know that, “Coefficient of performance” (COP)

$\mathrm{Cop}=\frac{Q}{w}$

$\mathrm{W}=\frac{Q}{\mathrm{cop}}$

Given that, COP = 3.2

$\mathrm{W}=\frac{1.6}{3.2}$

W = 0.5 kwh

The unit cost of electricity is $0.10/kWh

Unit electricity cost for 10 hours = 0.5 × 10 × 0.1$

Unit electricity cost for 10 hours = $0.5

The amount that is "vented out" by "the fans" is $0.50 for 10 hours.

6 0

3 years ago

I really need help on this question!

Alekssandra [29.7K]

Answer:

A - gamma-ray telescopes

Explanation:

Gamma rays have the shortest wavelengths of the electromagnetic spectrum, and are blocked by Earth's atmosphere. Therefore, gamma ray telescopes will be used to observe them. Hope this helps :)

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3 years ago

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In a parallel circuit, there is only one path for current to take. TRUE or FALSE.

harkovskaia [24]

False, Unless it is a series parallel circuit.

4 0

3 years ago