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3 years ago

A 4kg rock isn’t rolling 10m/s. Find it’s kinetic energy.

1 answer:

3 0

Kinetic energy = (1/2) (mass) (speed)²

The rock's kinetic energy is not

(1/2) (4 kg) (10 m/s)²

= (1/2) (4 kg) (100 m²/s²)

= 200 Joules .

It may be more, or it may be less. The only thing
we can be sure of is that it is not 200 Joules.

You might be interested in

5. Describe the shape of the waveform in the secondary coil for a sine, square and triangle wave in the primary coil. How does t

Volgvan

Answer:

When primary coil is exited by sin wave,this will result in sin wave in secondary coil as well.According to law,flux induced in the secondary coil will have same waveform as in the primary coil.

5 0

3 years ago

A skateboarder rolls off a 2.5 m high bridge into the river. If the skateboarder was originally moving at 7.0 m/s, how much time

saul85 [17]

Answer:

t = 0.714 s and x = 5.0 m

Explanation:

This is a projectile throwing exercise, in this case when the skater leaves the bridge he goes with horizontal speed

vₓ = 7.0 m / s

Let's find the time it takes to get to the river

y = y₀ + v_{oy} t - ½ g t²

the initial vertical speed is zero and when it reaches the river its height is zero

0 = y₀ + 0 - ½ g t²

t = $\sqrt{\frac{2y_o}{g} }$

t = ra 2 2.5 / 9.8

t = 0.714 s

the distance traveled is

x = vₓ t

x = 7.0 0.714

x = 5.0 m

3 0

3 years ago

Y=mx+b if y=8.18 m=1.31 b=17.2 then find x

Dafna1 [17]

Plug in the corresponding values into y = mx + b

8.18 in for y

1.31 in for m

17.2 in for b

8.18 = 1.31x + 17.2

Now bring 17.2 to the left side by subtracting 17.2 to both sides (what you do on one side you must do to the other). Since 17.2 is being added on the right side, subtraction (the opposite of addition) will cancel it out (make it zero) from the right side and bring it over to the left side.

8.18 - 17.2 = 1.31x

-9.02 = 1.31x

Then divide 1.31 to both sides to isolate x. Since 1.31 is being multiplied by x, division (the opposite of multiplication) will cancel 1.31 out (in this case it will make 1.31 one) from the right side and bring it over to the left side.

-9.02/1.31 = 1.31x/1.31

x ≈ -6.8855

x is roughly -6.89

Hope this helped!

~Just a girl in love with Shawn Mendes

8 0

3 years ago

Read 2 more answers

A sinusoidal sound wave moves through a medium and is described by the displacement wave function

ZanzabumX [31]

By applying the wave equation we know that the maximum speed of the element's oscillatory motion is 1716 micrometer / s.

We need to know about wave equations to solve this problem. The displacement of the wave on the y-axis can be explained by the wave equation

y = A cos (kx - ωt)

where y is y-axis displacement, A is amplitude, k is wave number, x is x-axis displacement, ω is angular speed and t is time.

the wavenumber and angular speed of the wave equation can be determined respectively by

k = 2π / λ

ω = 2πf

where k is the wavenumber, λ is wavelength and f is frequency.

From the question above, we know that:

y = 2.00cos (15.7x - 858t)

v = dy / dt

v = d(2.00cos (15.7x - 858t)) / dt

v = -858 x (-2.00sin(15.7x - 858t))

v = 1716 sin(15.7x - 858t) micrometer/s

maximum velocity can be reached when (sinθ = 1), hence

v = 1716 sin(15.7x - 858t)

v = 1716 x 1

v = 1716 micrometer / s

For more on wave equation on: brainly.com/question/25699025

#SPJ

4 0

2 years ago

A college student is working on her physics homework in her dorm room. Her room contains a total of 6.0 x 10^26 gas molecules. A

IceJOKER [234]

Answer:

Temperature, T = 3.62 kelvin

Explanation:

It is given that,

Total number of gas molecules, $N=6\times 10^{26}$

Her body is converting chemical energy into thermal energy at a rate of 125 W, P = 125 W

Time taken, t = 6 min = 360 s

Energy of a gas molecules is given by :

$\Delta E =\dfrac{3}{2}NkT$

$T=\dfrac{2E}{3Nk}$ , k is Boltzmann constant

$T=\dfrac{2\times P\times t}{3Nk}$

$T=\dfrac{2\times 125\times 360}{3\times 6\times 10^{26}\times 1.38\times 10^{-23}}$

T = 3.62 K

So, the temperature increases by 3.62 kelvin. Hence, this is the required solution.

4 0

3 years ago