Which of the following is a positive statement?

You go rock climbing with a pack that weighs 70 N and you reach a height of 30 m. how much work did you do to lift your pack? If

Vikentia [17]

When you climb, earth exerts gravitational force on pack in downward direction(pointing towards the center of earth).
In order to climb, you need to work against work done by gravity on the pack.
Hence work done by you = work done by gravity on pack
= Force x displacement = 70 x 30 = 2100 J.

So you need to do 2100 joules of work to lift your pack.

Power is the rate of work done.
Therefore power = work done by you/time(in seconds)
= 2100/600 =3.5 watts

8 0

4 years ago

A 250–g piece of gold is at 19 °C. 5.192 kJ of energy is added to it by heat. The specific heat of gold is 129 J/(kg·°C). Calcul

algol [13]

Answer:

A. DT is given by Q= MCs DT

m = mass of the substances

Cs= is it's specific heat capacity

Ck= Q

Mk ×DTk

=250 × 9 × 5

129

=Dt = 180.1085271

answer is 180degree C.

Explanation:

B. = 25×10 ×100

1.082

=2500

1.082

= 23105.360 g/kj.

7 0

3 years ago

what is the necessary condition within the hydrogen atom for balmer line photons to be absorbed by the hydrogen atom

luda_lava [24]

Explanation :

When an electron jumps from one energy level to another, the energy of atom gets changed.

If a photon gets absorbed, the electron will move to higher energy levels and then fall back to the lower energy levels. Then each time a photon will be absorbed whose energy is given by difference between the initial and final energy levels i.e

In Balmer series, the transition is from higher energy levels to n = 2.

So, the necessary condition for Balmer series is that the electron should be at first excited state or n = 2 level as shown in figure.

6 0

3 years ago

ASAP answer right and I will do a giveaway

Olenka [21]

Explanation:

Ans 1 ) As the gravity of a planet increases, there will be increase in thickness of atmosphere around that planet. The gravitational force of the planets holds the bulks of molecules of atmosphere (as gas will need higher escape velocity).

Ans 2) Mars is the easier planets among all other planets in our solar system as it lies in habitable zone and it as a moderate gravity (where live can survive). Well, there's lot of resources too.

Thanks for asking

6 0

3 years ago

Your physics teachers want to race each other using wagon rockets.

Genrish500 [490]

Answer:

s=1/2at^2

s=1/2 x 4 x(10)^2=200m

5 0

3 years ago