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3 years ago

Why are Murcury, venus, earth and mars called the "terrestrial" planets?

1 answer:

5 0

Mercury, Venus, Earth, and Mars are considered terrestrial planets because those planets are mainly composed of metal or rock and are closest to the sun.

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What is the si unit of force

Tcecarenko [31]

Explanation:

SI unit of force is <em>Newton</em>

3 0

3 years ago

Read 2 more answers

A mass of a spring vibrates in simple harmonic motion at a frequency of 8.0 Hz and an amplitude of 3.9 cm. If a timer is started

oee [108]

Answer:

e = 50.27 give / s

Explanation:

The expression for simple harmonic motion is

x = A cos (wt + Ф)

in this case they give us the amplitude A = 3.9 cm and frequency f = 8.0 Hz

The angular and linФear variables are related

e = 2π d

e = 2π 8

e = 50.27 give / s

let's look for the constant fi

so let's find the time to have the maximum displacement

v = dx / dt

v = -A w sin (wt +Ф)

for the point of maximum displacement the speed is I think

0 = - sin (0 + Ф)

therefore fi = 0

Let's put together the equation of motion

x = 0.039 sin (50.27 t)

v = 0.039 50.27 sin (50.27 3)

v = 1.96 50 0.01355

v = 0.0266 m / s

8 0

3 years ago

Anyone know the answer to this, would kindly appreciate it

Ipatiy [6.2K]

Answer:

The found value of r is:

r = 94.7

Explanation:

We know that

cosθ = Base / Hypotenuse

θ is the always the angle between base and hypotenuse

In this right angles triangle, the angle θ is given 63°.

Which means that the Base is 43 and the hypotenuse is r

Base = 43

Hypotenuse = r

Substitute θ=63°, Base = 43 and hypotenuse = r in the formula of cosθ mentioned above:

cos 63° = 43/r

Rearrange

r = 43/cos63°

r = 43/0.454

r= 94.7

6 0

3 years ago

A distracted driver is driving towards a turn where the edge of the road leads into a 75.0 m cliff. The velocity of the vehicle

Vlada [557]

As long as the car is on the road, it moves with a constant speed of 80km/h.

As soon as the car starts to fall down the cliff, it follows a parabolic motion. It means that it still moves with constant speed along the x axis, but it also starts to move along the y axis, with constant acceleration (i.e. the acceleration due to gravity).

The good thing about parabolic motions is that the two motions along the x and y axes are completely separable.

So, first of all, we need to know how long it takes for an object to fall for 75m. The equation of a constantly accelerated motion is

$s=s_0+v_0t+\dfrac{1}{2}at^2$

Where $s_0$ is the initial position, $v_0$ is the initial speed, and $a$ is the constant rate of acceleration. In our case, we start from an initial height of 75m, an initial (vertical!) speed of zero, and our acceleration is $-g$ . So, our equation becomes

$s=75-\dfrac{g}{2}t^2$

And we want to solve for the time when $s=0$ (i.e. we want to know how long will it take for the object to reach the ground). We have

$0=75-\dfrac{g}{2}t^2 \iff 75=\dfrac{g}{2}t^2 \iff \dfrac{2\cdot75}{g}=t^2 \iff t=\sqrt{\dfrac{150}{g}}$

(I'm discarding the negative solution because it wouldn't make sense)

Now that we've used the vertical motion to find out the falling time, we can go back to the horizontal motion. We know that the car moves for a certain amount of time at a certain speed. So, we simply have to plug our values in the $s=vt$ equation, to get