The height of the ball above the ground is 38.45 m
First we will calculate the velocity of the ball when it touch the ground by using first equation of motion
v=u+gt
v=0+9.81×2.8
v=27.468 m/s
now the height of the ground can be calculated by the formula
v=√2gh
27.468=√2×9.81×h
h=38.45 m
Answer:
Time required by boat 1 for the round trip is less than that of boat 2.
Hence, boat 1 wins.
Explanation:
Case 1: Boat 1
Speed of boat = 
time = 
While going to another end
time = 
time = 
time = 1 hour
While going back,
time = 
time = 
time = 1 hour
Total time taken by boat 1 is,
Total time by boat 1 = 1 hour + 1 hour = 2 hour
Total time by boat 1 = 2 hour
Total time taken by boat 1 for the round trip is 2 hour.
Case 2: Boat 2
Speed of boat = 
time = 
While going to another end
time = 
time = 
time = 2 hour
While going back,
time = 
time = 
time = 0.66 hour
Total time taken by boat 2 is,
Total time by boat 1 = 2 hour + 0.66 hour
Total time by boat 1 = 2.66 hour
Total time taken by boat 2 for the round trip is 2.66 hour.
Time required by boat 1 for the round trip is less than that of boat 2.
Hence, boat 1 wins.
Answer:
3- kinetic energy was transferred from the water to the ice
Explanation:
the kinetic energy in this situation is the molecules vibrating so the molecules in the ice absorb it and make the molecules not vibrate so it gets colder
After plugging all the data into the equation, the result of the relative centrifugal force (RCF) is measured in terms of g.
<h3>What is relative centrifugal force?</h3>
The relative centrifugal force (RCF) or the g force is the radial force generated by the spinning rotor as expressed relative to the earth's gravitational force.
RCF = ac/g
where;
- ac is centripetal acceleration
- g is acceleration due to gravity

where;
<h3>For example, </h3>
Find the maximum RCF of the JS-4.2 rotor can be obtained from its maximum speed (4200 rpm) and its rmax (250 mm);

Thus, after plugging all the data into the equation, the result is measured in terms of g.
Learn more about relative centrifugal force here: brainly.com/question/26887699
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