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2 years ago

Most of the energy on Earth comes from which of the following?

1 answer:

3 0

The earth gets most of its energy from the sun. The answer is letter B. This is because most of the living organisms on earth need sunlight to perform activities that would balance the ecosystem. Sunlight is the reason for the climate system on earth, the production of food through cellular respiration and many more.

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A cylinder fitted with a piston exists in a high-pressure chamber (3 atm) with an initial volume of 1 L. If a sufficient quantit

Bess [88]

Answer:

C. 85%

Explanation:

A cylinder fitted with a piston exists in a high-pressure chamber (3 atm) with an initial volume of 1 L. If a sufficient quantity of a hydrocarbon material is combusted inside the cylinder to produce 1 kJ of energy, and if the volume of the chamber then increases to 1.5 L, what percent of the fuel's energy was lost to friction and heat?

A. 15%

B. 30%

C. 85%

D. 100%

work done by the system will be

W=PdV

p=pressure

dV=change in volume

3tam will be changed to N/m^2

3*1.01*10^5

W=3.03*10^5*(1.5-1)

convert 0.5L to m^3

5*10^-4

W=3.03*10^5*5*10^-4

W=152J

therefore

to find the percentage used

152/1000*100

15%

100%-15%

85% uf the fuel's energy was lost to friction and heat

6 0

2 years ago

A projectile is launched with an initial velocity of (40 m/s), at an angle of (30°) above

zlopas [31]

Answer:

330.5 m

Explanation:

In this case, the object is launched horizontally at 30° with an initial velocity of 40 m/s .

The maximum height will be calculated as;

$h=\frac{v^2_isin^2\alpha }{2g}$

where ∝ is the angle of launch = 30°

vi= initial launch velocity = 40 m/s

g= 10 m/s²

h= 40²*sin²40° / 2*10

h={1600*0.4132 }/ 20

h= 661.1/2 = 330.5 m

8 0

2 years ago

Help A. 12,240 B. 6,120

nata0808 [166]

Answer:

A. 12,240.

Explanation:

1,530 times 8.0 = 12,240.

hope this helped :)

3 0

2 years ago

A bike moves 60 meters in 12 second. calculate the speed of the bike

nikdorinn [45]

Answer:

Speed=Distance

Time

=60

=5m/s

4 0

2 years ago

You have your bicycle upside down for repairs, with is 66.0 cm diameter wheel spinning freely at 230 rpm. The wheel's mass is 1.

rosijanka [135]

Answer:

$\omega_f = 17.86\ rad/s$

Explanation:

given,

dia of wheel = 66 cm

radius = 33 cm = 0.33 m

mass of wheel = 1.90 Kg

speed of wheel = 230 rpm

time to hold the tire = 3.10 s

Normal force = 2.7 N

coefficient of friction = 0.46

final angular speed = ?

we know

F = μ N

F = 0.46 x 2.7 = 1.242 N

torque

τ = F r

τ = 1.242 x 0.33 = 0.409 Nm

moment of inertia for wheel

I = MR²

I = 1.90 x 0.33²

I = 0.2069 kg m²

we now,

τ = I x α

$\alpha = \dfrac{\tau}{I}$

$\alpha = \dfrac{0.409}{0.2069}$

α = 1.981 rad/s²

we know,

$\omega_f - \omega_i = \alpha\ t$

$\omega_f - (230\dfrac{2\pi}{60}) =- 1.981 \times 3.1$

$\omega_f - 24 = - 6.14$

$\omega_f = 17.86\ rad/s$

7 0

2 years ago