Pleaseeee help I will mark brainless I don’t have long to complete this please help please

A race car's velocity increases from +28 m/s to +36 m/s over a 2.0-s time interval. What is the car's

BigorU [14]

Answer:

$4 m/s^{2}$

Explanation:

Acceleration, $a=\frac {v-u}{t}$

Where v and u are the final and initial velocities of the race car respectively, t is the time taken for the race car to attain velocity of 36 m/s.

Substituting 36 m/s for v, 28 m/s for u and 2 s for t then

$a=\frac {36 m/s-28 m/s}{2}=4 m/s^{2}$

3 0

3 years ago

The star Betelgeuse is 6.1 x 10^18 m away from Earth. How old is the light we see from that star when it reaches us? There are 3

castortr0y [4]

Answer:

635 years old

Explanation:

The light reaching the earth from the sun will travel at a speed called the speed of light, and this has a universal value of 3 × 10⁸ m/s. Bearing this in mind, let us calculate the age of the light reaching the Earth from the sun:

Distance of star from Earth = 6.1 × 10⁸m

Speed of light = 3 × 10⁸ m/s

We have distance and speed, let us calculate the time of travel of the light from the star to the earth.

Distance = speed × time

6.1 × 10⁸ = 3 × 10⁸ × time

$time = \frac{6.1 \times 10^{18}}{3 \times 10^8}$

In order to do the division above, we will divide the whole numbers normally, then we will apply the law of indices to the power that says:

Xᵃ ÷ Xᵇ = X⁽ᵃ⁻ᵇ⁾

$\therefore time = \frac{6.1 \times 10^{18}}{3 \times 10^8}\\= \frac{2.03 \times 10^{(18-8)}}{1} \\= 2.03 \times 10^{10}}\ seconds$

Next, we are told that there are 3.2 × 10⁷ seconds in a year.

∴ The number of years travelled by the light from the star:

$3.2\ \times 10^7\ seconds = 1\ year\\1\ second = \frac{1}{3.2\ \times 10^7} \\\therefore 2.03 \times 10^{10}\ seconds = \frac{2.03 \times 10^{10}}{3.2\ \times 10^7}$

please note that:

2.03 × 10¹⁰ = 20300000000

3.2 × 10⁷ = 32000000

$\therefore \frac{2.03 \times 10^{10}}{3.2\ \times 10^7}\\= \frac{20300000000}{32000000} \\\\= \frac{20300}{32} \\= 634.347\ years\\$

The closest answer in the option is 635 years, and we are short of this by some points due probably to approximations in the calculation.

8 0

3 years ago

PLEASE ANSWERRRRR ASAPPPPPP

Bad White [126]

D Valence
.
.
^^^answer

5 0

3 years ago

Read 2 more answers

When atoms form a bond, it is usually because each atom acquires a more stable arrangement of electrons in its electron shells.

liraira [26]

C. Usually when an atom loses or gains an electron, it is because it is trying to satisfy the Octet Rule. The Octet Rule states that an atom is at its stablest when it has 8 valence electrons (two in helium's case)

If you look on the periodic table, elements on the left (Alkaline Metals) are the most reactive because they only have one valence electron (or electron in the outer shell). Elements on the right (Noble Gases) are the least reactive because they have a full outer shell of 8 valence electrons.

Later on you will find that as stability decreases as you go down the periodic table but that is a discussion for a different time.

4 0

3 years ago

Read 2 more answers

A car is a compound machine true or false

Viktor [21]

True is the answer. I believe

6 0

3 years ago