Answer:
Explanation:
mass of the fellow ( m ) = 66kg
acceleration of fellow a
v = u + at
4.5 = 0 + a x 2
a = 4.5 /2
= 2.25 m / s²
Net force acting on fellow in upward direction by the surface of elevator
R - mg where R is reaction force of the surface of the elevator
Applying Newton's law of motion
R - mg = ma
R = m (g +a )
= 66 x ( 9.8 + 2 )
= 778.8 N
This will be the scale reading .
I think this is the answer. I hope you can understand.
About 13.7 billion years ago
The Big Bang Theory states that the universe started about 13.7 billion years ago, and before that, everything was in 1 singularity.
Answer: 24.7 km/h
Explanation:
1) Average speed definition and formula
The average speed is the total distance run divided by the time elapsed:
S = distance / time
2) Distance 1 = 67 km
3) Distance 2 = 81 km
4) Total distance traveled = 67 km + 81 km = 148 km
5) time 1 = 1 hour
6) time 2 = 5 hours
7) total time = time 1 + time 2 = 1 h + 5 h = 6 h
8) Average speed:
S = 148 km / 6 h = 24.7 km/h
Helium is lighter than air from the lungs.
Explanation:
A balloon filled with the air from lungs will sink to the ground but a balloon filled with Helium floats because helium is lighter than air.
Air is a mixture of many gases.
The air from the lungs is predominantly made up of carbon dioxide and water vapor.
- Gram per mole of carbon dioxide is 44. Water vapor is 18.
- Compared to helium which is 4, we see that the gas is lighter.
- Since the gas is lighter, it will float in air.
- The main component of air around us is nitrogen gas with a gram per mole of 28.
- A balloon filled with more of air from the lungs weigh more than that will filled air around and even far more than helium gas.
- This will cause a helium filled balloon to float.
learn more:
Density brainly.com/question/1698555
#learnwithBrainly