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Svetach [21]
3 years ago
6

The height (in meters) of a projectile shot vertically upward from a point 2 m above ground level with an initial velocity of 23

.5 m/s is h = 2 + 23.5t − 4.9t2 after t seconds. (Round your answers to two decimal places.) (a) Find the velocity after 2 s and after 4 s. v(2) = m/s v(4) = m/s
Physics
1 answer:
Burka [1]3 years ago
8 0

Answer:

a) v(2) = 3.9\,\frac{m}{s}, b) v(4) = -15.7\,\frac{m}{s}

Explanation:

a) The equation for vertical velocity is obtained by deriving the function with respect to time:

v(t) = 23.5 -9.8\cdot t

The velocities at given instants are, respectivelly:

v(2) = 3.9\,\frac{m}{s}

v(4) = -15.7\,\frac{m}{s}

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An example of an aerobic activity would be A, Cross-country skiing
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3 years ago
Question 13 of 20
Dominik [7]

Answer:

B. It has a central nucleus composed of 29 protons and 35 neutrons,

surrounded by an electron cloud containing 29 electrons.

Explanation:

Protons and neutrons are the only subatomic particles with mass, and they are located in the nucleus. If this atom has an atomic number of 29 and is copper, it must have 29 protons (protons define which element is being observed). This means all remaining mass is from neutrons. 64-29 = 35.

Electrons have no mass and orbit the nucleus in the electron cloud. Since this copper atom is neutral (we are not told it has a charge), there must be an equal number of protons and electrons.

6 0
3 years ago
Read 2 more answers
An x-ray beam of wavelength 1.4×10−10m makes an angle of 20° with a set of planes in a crystal(the Bragg angle)causing first ord
Gnom [1K]

Answer:

Second order line appears at 43.33° Bragg angle.

Explanation:

When there is a scattering of x- rays from the crystal lattice and interference occurs, this is known as Bragg's law.

The Bragg's diffraction equation is :

n\lambda=2d\sin\theta      .....(1)

Here n is order of constructive interference, λ is wavelength of x-ray beam, d is the inter spacing distance of lattice and θ is the Bragg's angle or scattering angle.

Given :

Wavelength, λ = 1.4 x 10⁻¹⁰ m

Bragg's angle, θ = 20°

Order of constructive interference, n =1

Substitute these value in equation (1).

1\times1.4\times10^{-10} =2d\sin20

d = 2.04 x 10⁻¹⁰ m

For second order constructive interference, let the Bragg's angle be θ₁.

Substitute 2 for n, 2.04 x 10⁻¹⁰ m for d and 1.4 x 10⁻¹⁰ m for λ in equation (1).

2\times1.4\times10^{-10} =2\times2.04\times10^{-10} \sin\theta_{1}

\sin\theta_{1} =0.68

<em>θ₁ </em>= 43.33°

4 0
3 years ago
An airport has runways only 198 m long. a small plane must reach a ground speed of 39 m/s before it can become airborne. what av
Anarel [89]
S: 198 m 
v=39 m/s 
u=0
t=? 
a=?

v²=u²+2as
(39)²=(0)²+2(a)(198) 
1521=396a
1521/396=a
3.84 m/s^2 = a 

Hope I helped :) 
8 0
4 years ago
The battery of a flashlight develops 3 V, and the current through the bulb is 200 mA.What power is absorbed by the bulb?
Verizon [17]

Answer : The power absorbed by the bulb is, 0.600 W

Explanation :

As we know that,

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Given:

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Now put all the given values in the above formula, we get:

Power = Voltage × Current

Power = 3V × 0.200 A

Power = 0.600 W

Thus, the power absorbed by the bulb is, 0.600 W

3 0
3 years ago
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