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3 years ago

What is dark energy?

1 answer:

4 0

Dark energy is a theoretical repulsive energy that causes the acceleration to the expansion of the universe. Among the choices, the nearest answer would be D. Dark energy can also be defined as a new form of energy, that is a dynamic field that fills up space but has an effect opposite to that of normal energy.

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A force of 8 N accelerates by 4 m/s^2. What would be the amount of force needed to give a final acceleration of 5.3 m/s^2

Elis [28]

Answer:

10.6 N

Explanation:

F = ma

8 = m * 4

m = 2 kg

F = 2 * 5.3

F = 10.6 N

4 0

3 years ago

An ice-skater with a mass of 80kg is holding a bowling ball with a mass of 8 kg. Suppose that the skater tosses the bowling ball

musickatia [10]

Answer:

0.6 m/s

Explanation:

The details of the masses and velocities are;

The mass of the ice skater, m₁ = 80 kg

The mass of the ball, m₂ = 8 kg

The speed with which the skater tosses the ball forward, v₂ = 6 m/s

Therefore;

According to the principle of conservation of linear momentum, we have;

m₁·v₁ = m₂·v₂

Where;

v₁ = The skater's reactive velocity

Therefore, we get;

80 kg × v₁ = 8 kg × 6 m/s

v₁ = 8 kg × 6 m/s/(80 kg) = 0.6 m/s

The skater's reactive velocity, v₁ = 0.6 m/s.

8 0

3 years ago

Page is

Ede4ka [16]

Answer:

72 m

Explanation:

Given:

v₀ = 0 m/s

v = 60 m/s

a = 25 m/s²

Find: Δx

v² = v₀² + 2aΔx

(60 m/s)² = (0 m/s)² + 2 (25 m/s²) Δx

Δx = 72 m

6 0

3 years ago

A sharp edged orifice with a 60 mm diameter opening in the vertical side of a large tank discharges under a head of 6 m. If the

Ierofanga [76]

Answer:

The discharge rate is $Q = 0.0192 \ m^3 /s$

Explanation:

From the question we are told that

The diameter is $d = 60 \ mm = 0.06 \ m$

The head is $h = 6 \ m$

The coefficient of contraction is $Cc = 0.68$

The coefficient of velocity is $Cv = 0.92$

The radius is mathematically evaluated as

$r = \frac{d}{2}$

substituting values

$r = \frac{ 0.06 }{2}$

$r = 0.03 \ m$

The area is mathematically represented as

$A = \pi r^2$

substituting values

$A = 3.142 * (0.03)^2$

$A = 0.00283 \ m^2$

The discharge rate is mathematically represented as

$Q = Cv *Cc * A * \sqrt{ 2 * g * h}$

substituting values

$Q = 0.68 * 0.92* 0.00283 * \sqrt{ 2 * 9.8 * 6}$

$Q = 0.0192 \ m^3 /s$

6 0

3 years ago

We have a toy gun with a spring constant of 50 N/m. The spring is compressed by 0.2 m. If you neglect friction and the mass of t

Arisa [49]

Answer:

$31.6\:\mathrm{m/s}$

Explanation:

The elastic potential energy of a spring is given by $Us=\frac{1}{2}kx^2$ , where $k$ is the spring constant of the spring and $x$ is displacement from point of equilibrium.

When released, this potential energy will be converted into kinetic energy. Kinetic energy is given by $KE=\frac{1}{2}mv^2$ , where $m$ is the mass of the object and $v$ is the object's velocity.

Thus, we have:

$Us=KE,\\\frac{1}{2}kx^2=\frac{1}{2}mv^2$

Substituting given values, we get:

$\frac{1}{2}\cdot 50\cdot 0.2^2=\frac{1}{2}\cdot 0.002\cdot v^2,\\v^2=\frac{50\cdot 0.2^2}{0.002},\\v^2=1000,\\v\approx \boxed{31.6\:\mathrm{m/s}}$

4 0

3 years ago