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3 years ago

How do l calculate e nergy

Physics

1 answer:

aivan3 [116]3 years ago

4 0

The formula for energy of motion is KE = .5 x m x v^2

Ke= Kinetic Energy in Joules

m = Mass in Kilograms

v = Velocity in Meters per Second

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Two forces are applied to a 17 kg box, as shown. The box is on a smooth surface. Which statement best describes the acceleration

RoseWind [281]

To the picture the answer is A. I can’t answer the typed question because I need the picture for the box

7 0

3 years ago

Light is incident along the normal to face AB of a glass prism of refractive index 1.54. Find αmax, the largest value the angle

marusya05 [52]

To solve this problem it is necessary to use the concepts related to Snell's law.

Snell's law establishes that reflection is subject to

$n_1sin\theta_1 = n_2sin\theta_2$

Where,

$\theta =$ Angle between the normal surface at the point of contact

n = Indices of refraction for corresponding media

The total internal reflection would then be given by

$n_1 sin\theta_1 = n_2sin\theta_2$

$(1.54) sin\theta_1 = (1.33)sin(90)$

$sin\theta_1 = \frac{1.33}{1.54}$

$\theta = sin^{-1}(\frac{1.33}{1.54})$

$\theta = 59.72\°$

Therefore the $\alpha_{max}$ would be equal to

$\alpha = 90\°-\theta$

$\alpha = 90-59.72$

$\alpha = 30.27\°$

Therefore the largest value of the angle α is 30.27°

3 0

3 years ago

Which is an example of how the body maintains homostasis

strojnjashka [21]

Answer:

lemme see

Explanation:

5 0

3 years ago

Read 2 more answers

How much heat (in kJ) is needed to convert 866 g of ice at −10°C to steam at 126°C? (The specific heats of ice and steam are 2.0

elena-14-01-66 [18.8K]

Answer:

2671.3 kJ

Explanation:

m = 866 g at - 10 degree C converts into steam at 126 degree C.

The following steps are there

(1) ice at - 10 degree C converts into ice at 0 degree C

H1 = m x specific heat of ice x ΔT

H1 = 866 x 2.03 x 10 = 17579.8 J

(ii) ice at 0 degree C converts into water at 0 degree C

H2 = m x Latent heat of fusion = 866 x 334 = 289244 J

(iii) water at 0 degree C converts into water at 100 degree C

H3 = m x specific heat of water x ΔT

ΔH3 = 866 x 4.186 x 100 = 362507.6 J

(iv) water at 100 degree C converts into steam at 100 degree C

H4 = m x Lateant heat of vaporisation

H4 = 866 x 2260 = 1957160 J

(v) seam at 100 degree C converts into steam at 126 degree C

H5 = m x specific heat of steam x ΔT

H5 = 866 x 1.99 x 26 = 44806.84 J

The total heat required is

H = H1 + H2 + H3 + H4 + H5

H = 2671298.24 J = 2671.3 kJ

8 0

3 years ago

An electron, traveling at a speed of 5.90 × 10 6 5.90×106 m/s, strikes the target of an X-ray tube. Upon impact, the electron de

Trava [24]

Answer:

$2.84\cdot 10^{-8} m$

Explanation:

Due to the law of conservation of energy, the energy of the emitted X-ray photon is equal to the energy lost by the electron.

The initial kinetic energy of the electron is:

$K_i = \frac{1}{2}mv_i^2 = \frac{1}{2}(9.11\cdot 10^{-31}kg)(5.90\cdot 10^6 m/s)^2=1.59\cdot 10^{-17}J$

The electrons decelerates to 3/4 of its speed, so the new speed is

$v_f = \frac{3}{4}v_i = \frac{3}{4}(5.90\cdot 10^6 m/s)=4.425\cdot 10^6 m/s$

So the final kinetic energy is

$K_f = \frac{1}{2}mv_f^2=\frac{1}{2}(9.11 \cdot 10^{-31} kg)(4.425\cdot 10^6 m/s)^2=8.9\cdot 10^{-18} J$

So, the energy lost by the electron, which is equal to the energy of the emitted photon, is

$E=K_i - K_f =1.59\cdot 10^{-17} J-8.9\cdot 10^{-18} J=7\cdot 10^{-18} J$

The wavelength of the photon is related to its energy by

$\lambda=\frac{hc}{E}$

where h is the Planck constant and c the speed of light. Substituting E, we find

$\lambda=\frac{(6.63\cdot 10^{-34}Js)(3\cdot 10^8 m/s)}{7\cdot 10^{-18} J}=2.84\cdot 10^{-8} m$

4 0

3 years ago