A few alpha particles bounce off a thin sheet of gold foil. What did scientists

A child whose weight is 276 N slides down a 5.90 m playground slide that makes an angle of 34.0° with the horizontal. The coeffi

garik1379 [7]

Answer:

Explanation:

Frictional force acting on the child = μ mg cosθ

, μ is coefficient of kinetic friction , m is mass of child θ is inclination

work done by frictional force

μ mg cosθ x d , d is displacement on inclined plane

work done = .13 x 276 x cos34 x 5.9

= 175.5 J

This work will be converted into heat energy.

b ) Initial energy of child = mgh + 1/2 m v ² , h is height , v is initial velocity

= 276 x 5.9 sin34 + 1/2 x 276 / 9.8 x .518² [ mass m = 276 / g ]

= 910.59 + 3.77

= 914.36 J

loss of energy due to friction = 175.5

Net energy at the bottom

= 738.86 J

If v be the velocity at the bottom

1/2 m v² = 738 .86

.5 x (276 / 9.8) x v² = 738.86

v² = 52.47

v = 7.24 m /s .

4 0

3 years ago

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In a cyclic process, a gas performs 123 J of work on its surroundings per cycle. What amount of heat, if any, transfers into or

Aleks04 [339]

Answer:

123 J transfer into the gas

Explanation:

Here we know that 123 J work is done by the gas on its surrounding

So here gas is doing work against external forces

Now for cyclic process we know that

$\Delta U = 0$

so from 1st law of thermodynamics we have

$dQ = W + \Delta U$

$dQ = W$

so work done is same as the heat supplied to the system

So correct answer is

123 J transfer into the gas

4 0

3 years ago

In 1965 Penzias and Wilson discovered the cosmic microwave radiation left over from the Big Bang expansion of the universe. The

HACTEHA [7]

Answer:

electric ﬁeld amplitude is 0.1133 V/m

Explanation:

given data

energy density = 5.69 × 10^−14 J/m3

speed of light = 2.99792 × 10^8 m/s

permeability of free space = 4π × 10^−7 N/A2

to find out

corresponding electric ﬁeld amplitude

solution

we know electric filed amplitude E is

E = BC ..............1

so first we find magnetic filed B from energy density

that is energy density

u = B²/ 2µ

so B = √2µu

put value

B = √2(4π× $10^{-7}$ ×5.69 × $10^{-14}$ )

B = 3.780645 × $10^{-10}$

so from equation 1

E = 3.780645 × $10^{-10}$ (2.99792 × 10^8)

E = 0.1133

electric ﬁeld amplitude is 0.1133 V/m

5 0

4 years ago

A bullet having the mass of 110g is fired. If it's velocity is 50m/s, calculate the kinetic energy

Papessa [141]

$\text{Kinetic energy,}\\\\E_k = \dfrac 12 mv^2\\\\~~~~~=\dfrac 12 \cdot 110 \times 10^{-3} \cdot 50^2\\\\~~~~~=137.5~ \text{J}$

7 0

3 years ago

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Please help me to find what the factors affecting gravity are. 10 points !

Nataly [62]

Answer:

Universal Gravitation, it is a force that keeps the moon orbiting around earth (or you could also add "it is the force that keeps all planets in our solar system orbiting around the sun.'

Explanation:

Well, my teacher taught me that the "Big blue title" is the question and the "red title" would be your answer.

(I hope this helps! and i'm sorry if the answer is wrong.)

-I tried.

4 0

4 years ago