Answer:
200 km/hr
Explanation:
Since he goes 80km per hour, multiply this by 2.5 or two and a half hours.
80 x 2.5 = 200 km/hr.
The speed of something in any given direction.
Answer:
Option A
Explanation:
The statement makes sense since it's already explained that the galaxy is moving away from us and unlike option C which depicts that the galaxy is moving to us.
This statement makes sense. The redshift means that we see the galaxy moving away from us, so observers in that galaxy must also see us moving away from them—which means they see us redshifted as well
Answer:
102000 kg
Explanation:
Given:
A total Δν = 15 km/s
first stage mass = 1000 tonnes
specific impulse of liquid rocket = 300 s
Mass flow rate of liquid fuel = 1500 kg/s
specific impulse of solid fuel = 250 s
Mass flow of solid fuel = 200 kg/s
First stage burn time = 1 minute = 1 × 60 seconds = 60 seconds
Now,
Mass flow of liquid fuel in 1 minute = Mass flow rate × Burn time
or
Mass flow of liquid fuel in 1 minute = 1500 × 60 = 90000 kg
Also,
Mass flow of solid fuel in 1 minute = Mass flow rate × Burn time
or
Mass flow of solid fuel in 1 minute = 200 × 60 = 12000 kg
Therefore,
The total jettisoned mass flow of the fuel in first stage
= 90000 kg + 12000 kg
= 102000 kg
Water gets to the leaves in the tops of the tallest trees by something called the cohesion-tension theory. Water has two very unique properties called adhesion and cohesion. Cohesion is the tendency of water molecules to stick together with one another. The water sticks together, leaving no room for air, strengthening the "force" of the water going up the tree. The water also sticks to the sides of the xylem inside the tree. In addition to these properties, there are also the factors of negative and positive water potential. For more information, look up more details of the cohesion-tension theory.
