Answer:
The answer is C)The force of gravity from Earth acting on the spacecraft decreased because the distance from Earth increased.
Explanation:
Gravity, a force, is dependent on the mass of the object exerting the gravity and the distance of an outside object from that object. The larger the object, the more gravity it will exert on an outside object. This force decreases as you move away from the object, but it will always still exist and never be equal to 0.
Answer:
2156J
Explanation:
Given parameters:
Height of lift = 10m
Mass = 22kg
Unknown:
Work done by the machine = ?
Solution:
Work done is the force applied to move a body through a certain distance.
So;
Work done = Force x distance
Here;
Work done = mass x acceleration due to gravity x height
Work done = 22 x 9.8 x 10 = 2156J
Answer:
Choice C is not equivalent to 2.50 miles.
Explanation:
The given data is now converted into feet, inches, kilometers, yards and centimeters:
mi - ft


(Choice A)
mi - in


(Choice B)
mi - km

(Different from Choice C)
mi - yd


(Choice D)
mi - cm


(Choice E)
Choice C is not equivalent to 2.50 miles.
Answer:
The speed of the plank relative to the ice is:

Explanation:
Here we can use momentum conservation. Do not forget it is relative to the ice.
(1)
Where:
- m(g) is the mass of the girl
- m(p) is the mass of the plank
- v(g) is the speed of the girl
- v(p) is the speed of the plank
Now, as we have relative velocities, we have:
(2)
v(g/b) is the speed of the girl relative to the plank
Solving the system of equations (1) and (2)



I hope it helps you!