A billiard ball rolls from rest down a smooth ramp that is 8.0 m long. the acceleration of the ball is constant at 2.0?

A car travels due east 14 miles in 18 minutes. Then, the car turns around and returns to its starting point, taking an additiona

N76 [4]

Answer:

(a) The average speed is 0.85 milles/minute

(b) The average velocity is zero

Explanation:

In order to answer part (a) and (b) you have to apply the formulas for average speed and average velocity which are:

<em>-Average speed formula:</em>

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

where d is the total distance traveled and t is the tota time

Replacing the given values:

$v=\frac{14+14}{18+15}\\v=\frac{28}{33} \\v=0.85$ milles/minute

Notice that you have to replace the total distance, which is 14 milles for the go plus 14 milles for the return. The same for the total time.

<em>-Average velocity formula:</em>

V = Δx/Δt

Where V is the velocity vector, Δx is the displacement and Δt is the change in time

V= $\frac{X2-X1}{t2-t1}$

Where X2 is the final position and X1 is the initial position

In this case X1= 0 i and X2=0 i (i is the unit vector in the x direction). So, the displacement is zero.

Therefore, the average velocity is:

V= 0 i [milles/minute]

4 0

3 years ago

A 210 Ohm resistor uses 9.28 W of

IgorLugansk [536]

Resistance=R=210Ohm
Power=9.28W=P

Current=I

$\boxed{\sf P=I^2R}$

$\\ \sf\longmapsto I^2=\dfrac{P}{R}$

$\\ \sf\longmapsto I^2=\dfrac{9.28}{210}$

$\\ \sf\longmapsto I^2\approx0.04$

$\\ \sf\longmapsto I\approx\sqrt{0.04}$

$\\ \sf\longmapsto I\approx\sqrt{\dfrac{4}{100}}$

$\\ \sf\longmapsto I\approx\dfrac{\sqrt{4}}{\sqrt{100}}$

$\\ \sf\longmapsto I\approx\dfrac{2}{10}$

$\\ \sf\longmapsto I\approx0.2A$

4 0

3 years ago

PLEASE ANSWER THIS ASAP I WILL MARK YOU THE BRAINLIEST The actual subject is Science but they dont have that as a option in pick

Sophie [7]

Explanation:

speed : • how fast an object changes position

• miles per hour.

• distance/time.

velocity: • speed in a direction

• miles per hour North

• distance/ time in a direction

5 0

2 years ago

An object is falling from a height of 7.5 meters. At what height will it’s velocity be 7 meters/second?

Nady [450]

One of the equations of gravity is this:
${v}^{2} = {u}^{2} + 2gh$
Where v = final velocity which is 7m/s
u = initial velocity which is 0 for objects falling from a height
g = acceleration due to gravity and it is approximately 10m/s^2. It's a constant so pretty much remember this number. It's positive since the work being done is caused by gravity (in other words, it's falling down). It can also be negative if the work being down is against gravity (in other words, it's going up)
h = height of object

Substitute for the values and you should have something like this
${7}^{2} = {0}^{2} + 2 \times 10 \times h$
$49 = 0 + 20h$
$h = \frac{49}{20}$
$h = 2.5m$

6 0

3 years ago

Explain your results: How can Earth’s gravity affect the water when the water isn’t actually touching the Earth? (2 pts) Do you

Levart [38]

Answer:

Because the Earth has so much gravity, it can hold water, land, and life in it's atmosphere.

(Not sure what beaker you are talking about, so sorry) But I don't think the moon's gravity would have an effect on a beaker of water because the Earth's gravity is much more than the moon's.

I think you would be able to feel a little bit of Earth's gravity on the moon because the Earth's gravity pulled the moon into orbit, therefore, gravity on Earth my have some effect on the moon.

hope this helps!

5 0

3 years ago