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3 years ago

Help me with this PLEASEEEE!

Physics

2 answers:

larisa [96]3 years ago

5 0

Fossil and hydro energy have a nice day

yKpoI14uk [10]3 years ago

4 0

hydro energy IS a renewable source.

fossil fuels and nuclear are non-renewable.

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Which is an example of conduction?

densk [106]

Answer:

Touching the stove and getting burned, ice melting in your hand

Explanation:

7 0

3 years ago

Read 2 more answers

A particle is moving with velocity v(t) = t2 _ 9t + 18 with distance, s measured in meters, left or right of zero, and t measure

Alex787 [66]

V = t^2 - 9t + 18

position, s
s = t^3 /3 - 4.5t^2 +18t + C

 t = 0, s = 1 => 1=C => s = t^3/3 -4.5t^2 + 18t + 1

Average velocity: distance / time

 distance: t = 8 => s = 8^3 / 3 - 4.5 (8)^2 + 18(8) + 1 = 27.67 m
 Average velocity = 27.67 / 8 = 3.46 m/s

t = 5 s

 v = t^2 - 9t + 18 = 5^2 - 9(5) + 18 = -2 m/s
 speed = |-2| m/s = 2 m/s

Moving right
 V > 0 => t^2 - 9t + 18 > 0
 (t - 6)(t - 3) > 0

 => t > 6 and t > 3 => t > 6 s => Interval (6,8)

 => t < 6 and t <3 => t <3 s => interval (0,3)



Going faster and slowing dowm

acceleration, a = v' = 2t - 9
 a > 0 => 2t - 9 > 0 => 2t > 9 => t > 4.5 s
 Then, going faster in the interval (4.5 , 8) and slowing down in (0, 4.5)

4 0

2 years ago

2200 kg semi truck driving down the highway has lost control. The truck rolls across the median and into oncoming traffic. The t

serious [3.7K]

Answer:

The semi truck travels at an initial speed of 69.545 meters per second downwards.

Explanation:

In this exercise we see a case of an entirely inellastic collision between the semi truck and the car, which can be described by the following equation derived from Principle of Linear Momentum Conservation: (We assume that velocity oriented northwards is positive)

$m_{S}\cdot v_{S}+m_{C}\cdot v_{C} = (m_{S}+m_{C})\cdot v$ (1)

Where:

$m_{S}$ , $m_{C}$ - Masses of the semi truck and the car, measured in kilograms.

$v_{S}$ , $v_{C}$ - Initial velocities of the semi truck and the car, measured in meters per second.

$v$ - Final speed of the system after collision, measured in meters per second.

If we know that $m_{S} = 2200\,kg$ , $m_{C} = 2000\,kg$ , $v_{C} = 45\,\frac{m}{s}$ and $v = -15\,\frac{m}{s}$ , then the initial velocity of the semi truck is:

$m_{S}\cdot v_{S} = (m_{S}+m_{C})\cdot v -m_{C}\cdot v_{C}$

$v_{S} = \frac{(m_{S}+m_{C})\cdot v - m_{C}\cdot v_{C}}{m_{S}}$

$v_{S} = \left(1+\frac{m_{C}}{m_{S}} \right)\cdot v - \frac{m_{C}}{m_{S}} \cdot v_{C}$

$v_{S} = v +\frac{m_{C}}{m_{S}}\cdot (v-v_{C})$

$v_{S} = -15\,\frac{m}{s}+\left(\frac{2000\,kg}{2200\,kg} \right) \cdot \left(-15\,\frac{m}{s}-45\,\frac{m}{s} \right)$

$v_{S} = -69.545\,\frac{m}{s}$

The semi truck travels at an initial speed of 69.545 meters per second downwards.

3 0

2 years ago

A laser beam with a frequency of 180 Hz forms an 8 m standing wave with 10 nodes.

DIA [1.3K]

Answer:33

Explanation:

F = frequency

N = Node count

w = wave lenght

v = wave velocity

L = distance wave traveled

First find wave length of laser

w = (2/(N))*(L)

w = (2/(10))*(8)

w = 1.6

then using (w), find velocity

V = (w)(F)

V = (1.6)*(108)

V = 288

Plug in V and the new frequency to solve for new node count

F = NV/2L

(600) = (N)*(288) / 2 * (8)

(N) = 33.33

there are 33 nodes

8 0

3 years ago

Which is more dense, cold freshwater or warm seawater?

svp [43]

Cold freshwater is denser than warm seawater, because of the salinity and temperature variations. Cold water would have less salt since the solubility of the salt is lower as compared to warm water. Hope this answers the question. Have a nice day.

4 0

3 years ago

Read 2 more answers