On earth, what forces tend to slow an object down?

Which surface exhibits the highest albedo measurement

k0ka [10]

Fresh snow is the surface that exhibits the highest albedo measurement.

8 0

3 years ago

What are the advantages and disadvantages for methods used to reduce the impact of human activity?

Helga [31]

advantages

1.Less flooding

2.Less erosion

3.Return of natural ecosystems

disadvantages

1. People go hungry

2. People don't get the water they want

3. People don't get the land they want for homes

5 0

3 years ago

I would like help with this physics problem

Darina [25.2K]

(a) This is a freefall problem in disguise - when the ball returns to its original position, it will be going at the same speed but in the opposite direction. So the ball's final velocity is the negative of its initial velocity.

Recall that

$v_f=v_i+at$

We have $v_f=-v_i$ , so that

$-2v_i=at\implies-2\left(8\,\dfrac{\mathrm m}{\mathrm s}\right)=\left(-2\,\dfrac{\mathrm m}{\mathrm s^2}\right)t\implies t=8\,\mathrm s$

(b) The speed of the ball at the start and at the end of the roll are the same 8 m/s, so the average speed is also 8 m/s.

(c) The ball's average velocity is 0. Average velocity is given by $\dfrac{v_i+v_f}2$ , and we know that $v_f=-v_i$ .

(d) The position of the ball $x_f$ at time $t$ is given by

$x_f=x_i+v_it+\dfrac12at^2$

Take the starting position to be the origin, $x_i=0$ . Then after 6 seconds,

$x_f=\left(8\,\dfrac{\mathrm m}{\mathrm s}\right)(6\,\mathrm s)+\dfrac12\left(-2\,\dfrac{\mathrm m}{\mathrm s^2}\right)(6\,\mathrm s)^2=42\,\mathrm m$

so the ball is 42 m away from where it started.

We're not asked to say in which direction it's moving at this point, but just out of curiosity we can determine that too:

$x_f-x_i=\dfrac{v_i+v_f}2t\implies42\,\mathrm m=\dfrac{8\,\frac{\mathrm m}{\mathrm s}+v_f}2(6\,\mathrm s)\implies v_f=6\,\dfrac{\mathrm m}{\mathrm s}$

Since the velocity is positive, the ball is still moving up the incline.

8 0

3 years ago

Denial cycled at 6 mph for 0.8 h. Then he jogged at 2 mph for

dexar [7]

<h3>Deniel's average speed for the total</h3><h3>distance is 3.6 mph</h3>

Average speed is difined as the total distance travelled divided by the total time required to cover the distance. Mathematically, it is expressed as:

$Ave. Speed = \frac{Total distance }{Total time}$

To obtain the average speed of Daniel, we shall determine the distance travelled in each case. This is illustrated below:

Speed 1 (S₁) = 6 mph

Time 1 (t₁) = 0.8 h.

<h3>Distance 1 (D₁) =? </h3>

$Speed = \frac{Distance}{Time} \\\\S_{1} = \frac{D_{1}}{t_{1}} \\\\6 = \frac{D_{1}}{0.8}$

Cross multiply

D₁ = 6 × 0.8

Speed 2 (S₂) = 2 mph

Time 2 (t₂) = 1.2 h.

<h3>Distance 2 (D₂) =? </h3>

$S_{2} = \frac{D_{2}}{t_{2}}\\\\2 = \frac{D_{2}}{1.2}$

Cross multiply

D₂ = 2 × 1.2

Next, we shall determine the total time. This can be obtained as follow:

Time 1 (t₁) = 0.8 h.

Time 2 (t₂) = 1.2 h.

<h3>Total time (T) =? </h3>

T = t₁ + t₂

T = 0.8 + 1.2

Next, we shall determine the total distance. This can be obtained as follow:

Distance 1 (D₁) = 4.8 mile

Distance 2 (D₂) = 2.4 mile

<h3>Total distance (D) =?</h3>

D = D₁ + D₂

D = 4.8 + 2.4

Finally, we shall determine the average speed of Daniel. This can be obtained as follow:

Total time = 2 h

Total distance = 7.2 mile

<h3>Average speed =?</h3>

$Ave. speed = \frac{Total distance }{Total time} \\\\Ave. speed = \frac{7.2 }{2}$

<h3>Average speed = 3.6 mph</h3><h3 />

Therefore, the average speed of Daniel is 3.6 mph

Learn more: brainly.com/question/680492

5 0

3 years ago

I don’t know where each one goes

Usimov [2.4K]

I classified them by numbers 1 to 8
Force: #s 2,4,5,67
Friction: #s 1 3 8
That’s it what I would say its the answer

3 0

3 years ago