Question 11

Mike says, I gave up guitar because I’ll never be good at it, some people seem to have a good ear music, not me. Which mindset i

AveGali [126]

A negative mind set

8 0

2 years ago

What is it that lives if it is fed, and dies if you give it a drink?

Anna71 [15]

Fire is it that lives if it is fed, and dies if you give it a drink.

<h3><u>Explanation:</u></h3>

Fire is very essential part of human life. It is used for cooking food and for other important activities. Without fire we cannot not survive. Something or the other should be heated before consumption and this can be achieved only with fir. It is also used in the darker places for viewing many things around us.

Thus, fire can survive if we give fuel or any wooden pieces and when water is poured on it it will turn off. Hence Fire is the one that survives when it is fed and dies when water is given as a drink to it.

4 0

2 years ago

As part of an exercise program, a woman walks south at a speed of 2.00 m/s for 60.0 minutes. She then turns around and walks nor

Anastaziya [24]

Answer:

Option A

Solution:

As per the question:

The distance covered by the woman in the North direction, d = 3000 m

Time taken to travel in North direction, t = 25.0 min = 1500 s

Velocity of woman in the south direction, v = 2.00 m/s

Time taken in the south direction, t' = 60.0 min = 3600 s

Now,

The distance covered in the south direction, d' = vt' = $2.00\times 3600 = 7200\ m$

Now, the total displacement is given by:

D = d' - d = 7200 - 3000 = 4200 m in South

(a) Average velocity of the woman in the whole journey is given by:

$v_{avg} = \frac{Total\ displacement}{Total\ time} = \frac{4200}{t + t'}$

$v_{avg} = \frac{4200}{1500 + 3600} = 0.8235\ m/s$ ≈ 0.824 m/s South

6 0

2 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

paper by itself catches fire easily whereas a piece of paper wrapped around an alluminium pipe does not.

Julli [10]

Answer:

The paper does not catch fire when wrapped around aluminium pipe because aluminium absorbs the heat, so paper does not attain its ignition temperature.

Explanation:

7 0

2 years ago