The net force on a rock is 250 newtons downward. The rock accelerates at a rate of 10 m/s2. What is the rock's mass?

In 0.60 seconds, a projectile goes from 0 to 610 m/s. What is the acceleration of the projectile?

IceJOKER [234]

Answer: $a=1016.66 m/s^{2}$

Explanation:

Acceleration $a$ is expressed in the following formula:

$a=\frac{V_{f}-V_{o}}{t}$

Where:

$V_{f}=610 m/s$ is the final velocity of the projectile

$V_{o}=0 m/s$ is the initial velocity of the projectile

$t=0.6 s$ is the time

Solving:

$a=\frac{610 m/s-0 m/s}{0.6 s}$

$a=1016.66 m/s^{2}$ This is the acceleration of the projectile

6 0

3 years ago

A book is sitting on a desk. What best describes the normal force acting on the book?

hjlf

Answer:

umm im not sure

3 0

3 years ago

Earth travels fastest in January and slowest in July. What is the most likely explanation for this?

Keith_Richards [23]

Answer:

Earth is nearest the Sun in July and farthest away in July.

Explanation:

3 0

3 years ago

Read 2 more answers

The force of attraction between the opposite charges of the ions in an ionic compound

Contact [7]

The force of attraction between the opposite charges of the ions in an ionic compound is an ionic bond.

<u>Explanation:</u>

The transfer process of valence electron between atoms referred as ionic bond. This is a kind of chemical bonds which can create two oppositely charged ions. In the presence of ionic bonds, the metal loses electrons and becomes a positive charge cation, while non-metal accepts these electrons and becomes a negative charge anion.

Here, more than 1 electron can be emitted or received to meet the octet principle and the net charge of the compound should be zero. For example: Table salt. In this compound, sodium loses the electron to become $N a^{+}$ , while the chlorine loses the electron to become $c l^{-}$ .

7 0

3 years ago

Whenever two apollo astronauts were on the surface of the moon, a third astronaut orbited the moon. assume the orbit to be circu

almond37 [142]

Missing question:
"Determine (a) the astronaut’s orbital speed v and (b) the period of the orbit"

Solution

part a) The center of the orbit of the third astronaut is located at the center of the moon. This means that the radius of the orbit is the sum of the Moon's radius r0 and the altitude ( $h=430 km=4.3 \cdot 10^5 m$ ) of the orbit:
$r= r_0 + h=1.7 \cdot 10^6 m + 4.3 \cdot 10^5 m=2.13 \cdot 10^6 m$
This is a circular motion, where the centripetal acceleration is equal to the gravitational acceleration g at this altitude. The problem says that at this altitude, $g=1.08 m/s^2$ . So we can write
$g=a_c= \frac{v^2}{r}$
where $a_c$ is the centripetal acceleration and v is the speed of the astronaut. Re-arranging it we can find v:
$v= \sqrt{g r}= \sqrt{(1.08 m/s^2)(2.13 \cdot 10^6 m)}=1517 m/s = 1.52 km/s$

part b) The orbit has a circumference of $2 \pi r$ , and the astronaut is covering it at a speed equal to v. Therefore, the period of the orbit is
$T= \frac{2 \pi r}{v} = \frac{2\pi (2.13 \cdot 10^6 m)}{1517 m/s} =8818 s = 2.45 h$
So, the period of the orbit is 2.45 hours.

6 0

3 years ago