The answer is false. The speed of the astronaut cancels out the force of gravity, causing a 'stationary freefall'. While under these effects, it is not required for an astronaut to 'strengthen' his body.
Answer:
– 2.5 m/s²
Explanation:
We have,
• Initial velocity, u = 180 km/h = 50 m/s
• Final velocity, v = 0 m/s (it stops)
• Time taken, t = 20 seconds
We have to find acceleration, a.
a = (v ― u)/t
a = (0 – 50)/20 m/s²
a = –50/20 m/s²
a = – 5/2 m/s²
a = – 2.5 m/s² (Velocity is decreasing) [Answer]
Answer:

Explanation:
It is given that,
Depth of Death valley is 85 m below sea level, 
The summit of nearby Mt. Whitney has an elevation of 4420 m, 
Mass of the hiker, m = 65 kg
We need to find the change in potential energy. It is given by :



or

So, the change in potential energy of the hiker is
. Hence, this is the required solution.
<h2>Answer::</h2>
Humans (biosphere) built a dam out of rock materials (geosphere). Water in the lake (hydrosphere) seeps into the cliff walls behind the dam, becoming groundwater (geosphere), or evaporating into the air (atmosphere).','.