A car has a speed of 20 m/s. If the speed of the car increases to 30 m/s in 5 seconds, what is the car’s acceleration?

two girls drag a bag across the floor. One girl exerts a force of 10 newtons and the other girl a force of 30 Newton's in the sa

lara [203]

Answer:

Explanation:

The resultant would be a combination of the two forces. We need to add them together since they are exerting a force in the same direction.

10+30= 40 N of force

5 0

3 years ago

If the number of homes with a pet dog is equal to 250, how many total homes are repersented by the chart?

scoray [572]

500 because 250 x 2 = 500

3 0

3 years ago

In the visible spectra of stars, absorption lines of hydrogen are produced when atoms are excited from n = 2 to higher levels (t

grigory [225]

Answer:

3. relatively high temperature, about 10,000 K, so that significant numbers of electrons are excited from the ground state, n = 1, to the first excited state, n = 2, but not too many of them have been ejected completely from the atoms

Explanation:

If hydrogen absorption lines are very strong in the visible spectrum of a particular star that means the population of electron in n = 2 is very high so on being exited they absorb radiation in Balmer series and give rise to absorption spectrum. The average temperature required to excite electron in hydrogen atom from n=1 to n = 2 is 10000K .

4 0

3 years ago

A pulley with a radius of 3.0 cm and a rotational inertia of 4.5 x 10–3 kg∙m2 is suspended from the ceiling. A rope passes over

vekshin1

Answer:

22J

Explanation:

Given :

radius 'r'= 3cm

rotational inertia 'I'=4.5 x $10^{-3}$ kgm²