All categories

2 years ago

Answer the question below:

Physics

2 answers:

OLga [1]2 years ago

8 0

Answer:

Its D

Explanation:

Bezzdna [24]2 years ago

6 0

Answer:

D) the decay rates of radioactive uranium and lead

Explanation:

As we know that when she found the substance it must have some fixed ratio of radioactive uranium and Lead in that substance.

Here since Uranium is radioactive substance so it will continuously convert into Lead and this ratio will change with time

So here we can say that the ratio of radioactive uranium and lead will depend on its decay rate

now to find the age of the substance we can find the present ratio of lead and uranium in that substance and then compare it with freshly prepared substance.

so by the formula

we can find the age of the sample

You might be interested in

On Friday, September 28, 2018, Palu, Indonesia, on the island of Sulawesi, experienced an earthquake that generated a tsunami. F

Naily [24]

Answer: Proximity to active volcanoes

Explanation:

When volcanoes erupt, they can generate tsunamis in the following ways:

-Parts of the volcano (some of them may be underwater) could collapse, generating a big displacement of water and resulting in a tsunami.

-The magma chamber could also collapse as it empties, also generating water displacement.

-If the volcanoes are near to the shore, debris resulting from the eruption could hit the water at fast speeds, producing big waves and eventually a tsunami.

In this case, the proximity of Palu city to active volcanoes, especially ones that are so close to the shore, increases the risk of a tsunami.

7 0

3 years ago

In a local diner, a customer slides an empty coffee cup down the counter for a refill. The cup slides off the counter and strike

zysi [14]

a) $t=\sqrt{\frac{2h}{g}}$

b) $v=\frac{d}{\sqrt{\frac{2h}{g}}}$

c) $v=\sqrt{d^2(\frac{g}{2h})+(2gh)}$

d) $\theta=tan^{-1}(\frac{2h}{d})$ (radians)

Explanation:

The motion of the cup sliding off the counter is the motion of a projectile, consisting of two independent motions:

- A uniform motion along the horizontal direction

- A uniformly accelerated motion (free fall) along the vertical direction

The time of flight of the cup is entirely determined by the vertical motion, therefore we can use the suvat equation:

$s=ut+\frac{1}{2}at^2$

where here:

$s=h$ (the vertical displacement is the height of the counter)

$u=0$ (the initial vertical velocity of the cup is zero)

$a=g$ (the vertical acceleration is the acceleration of gravity)

Solving for t, we find the time of flight of the cup:

$h=0+\frac{1}{2}gt^2\\t=\sqrt{\frac{2h}{g}}$

To solve this part, we just analyze the horizontal motion of the cup.

Here we know that the horizontal motion of the cup is uniform: this means that is horizontal speed is constant during the whole motion, and it is actually equal to the speed at which the mug leaves the counter.

For a uniform motion, the speed is given by

$v=\frac{d}{t}$

where

d is the distance covered

t is the time taken

Here, the distance covered is $d$ , the distance from the base of the counter, while the time taken is the time of flight:

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

Substituting into the previous equation, we find the speed of the mug as it leaves the counter:

$v=\frac{d}{\sqrt{\frac{2h}{g}}}$

Here we want to find the speed of the cup immediately before it hits the floor.

Here we have to consider that while the mug falls, its vertical speed increases, while the horizontal speed remains constant.

Therefore, the horizontal speed of the cup before it hits the ground is:

$v_x=\frac{d}{\sqrt{\frac{2h}{g}}}=d\sqrt{\frac{g}{2h}}$

The vertical speed instead is given by the suvat equation:

$v_y=u_y + at$

where:

$u_y=0$ is the initial vertical velocity

$a=g$ is the acceleration

$t=\sqrt{\frac{2h}{g}}$ is the time of flight

Substituting,

$v_y = 0 +g(\sqrt{\frac{2h}{g}})=\sqrt{2gh}$

The actual speed of the cup just before it hits the floor is the resultant of the horizontal and vertical speeds, so it is:

$v=\sqrt{v_x^2+v_y^2}=\sqrt{d^2(\frac{g}{2h})+(2gh)}$

Just before hitting the floor, the velocity of the cup has two components:

$v_x=d\sqrt{\frac{g}{2h}}$ is the horizontal component (in the forward direction)

$v_y=\sqrt{2gh}$ is the vertical component (in the downward direction)

Since the two components are perpendicular to each other, the angle of the direction is given by the equation

$tan \theta = \frac{v_y}{v_x}$

where here $\theta$ is measured as below the horizontal direction.

Substituting the expressions for $v_x,v_y$ , we find:

$tan \theta = \frac{\sqrt{2gh}}{d\sqrt{\frac{g}{2h}}}=\frac{2h}{d}$

$\theta=tan^{-1}(\frac{2h}{d})$ (radians)

4 0

3 years ago

Help quick

Yanka [14]

C it reduces the amount of useful work done on objects move it up the ramp

8 0

3 years ago

A circuit contains four light bulbs. One light bulb goes out but the other three stays it. This must be an)

Paul [167]

Answer:

It is a parallel connection

Explanation:

In parallel connection the

Cell is not easily used up because the cells share the total current generated together with all bulbs.

But a major problem is the bulbs must not be left together undisconnected to avoid exhaustion arising from short fall in the strength of one cell as this bounds to affect others

3 0

3 years ago

Can you walk on the moon

morpeh [17]

You can. But the gravity on the moon is 1/6th the gravity on Earth. This means 300 lbs man would only weigh 50 lbs.

7 0

3 years ago

Read 2 more answers