120 minutes=2 hours
20/2= 10mph
If the earth's mass were half its actual value but its radius stayed the same, the escape velocity of the earth would be
.
<h3>What is an escape velocity?</h3>
The ratio of the object's travel distance over a specific period of time is known as its velocity. As a vector quantity, the velocity requires both the magnitude and the direction. the slowest possible speed at which a body can break out of the gravitational pull of a certain planet or another object.
The formula to calculate the escape velocity of earth is given below:-

Given that earth's mass was half its actual value but its radius stayed the same. The escape velocity will be calculated as below:-

.
Therefore, If the earth's mass were half its actual value but its radius stayed the same, the escape velocity of the earth would be
.
To know more about escape velocity follow
brainly.com/question/14042253
#SPJ4
Strong alien you got there good luck bud you never asked a question
Answer:
No, some energy will be dissipated energy due to work of air resistance.
Answer:
Option ( B ) is correct .
Explanation:
To lift a heavy weight , inclined plane is used . Use of inclined plane , makes the task easier because instead of force mg , force mg sinθ is to be used which is less than mg . Here θ is inclination of inclined plane.
If h be the height by which weight is to be lifted
potential energy acquired by weight = mgh
work done by force mg sinθ = mgsinθ x d where d is displacement required .
mg sinθ x d = mgh ( work done by force = potential energy stored in luggage )
d = h / sinθ
d will be more than h
Hence inclined plane increases the distance to be covered by force applied though it decreases the force itself.
Hence option ( B ) is correct .