Answer:
91 km
Explanation:
Draw a picture. The line of sight to the horizon forms a tangent line with the curvature of the Earth. The radius line to that point forms a right angle with the tangent line. So we can use Pythagorean theorem to find the distance.
c² = a² + b²
(6400 km + 0.650 km)² = (6400 km)² + d²
d ≈ 91 km
These are digital signals.
Answer:
0.52 m
Explanation:
The motion of the studnet is an accelerated motion, with constant acceleration 
(acceleration of gravity) toward the ground. We can find the distance covered by the student (which is equal to the height from which he falls) by using the SUVAT equation:
where
v = 3.2 m/s is the final speed
u = 0 is the initial speed
a = 9.8 m/s^2 is the acceleration
d is the distance covered
By re-arranging the equation, we find:
The man is holding the suitcase at the same height above the surface of earth. So the gravitation potential energy remains the same.
<span>work done is force * displacement = weight * 0 = 0</span>
