Answer:
44.5s ; 22.64 m/s
Explanation:
The motion of the truck could be separated into 3 different phases :
First :
Time of motion :
Initial Velocity, u = 0 ; final velocity, v = 29 m/s
Acceleration, a = 2 m/s²
Recall: acceleration = change in velocity / time
Time = change in velocity / acceleration
Time = (29 - 0) / 2 = 14.5 second
Distance traveled = ((29 + 0) /2) * 14.5 = 210.25 m
Second :
Time = 25 seconds at constant speed
29 m/s for 25 seconds
v*t = 29 * 25 = 725 m
Third:
5 seconds before coming to rest
((29 + 0) /2) * 5
14.5 * 5 = 72.5 m
A.)
Length of journey = (14.5+ 25 + 5) = 44.5 seconds
B.)
Average velocity = total distance / total time taken
Average velocity = (210.25 + 725 + 72.5) / 44.5
= 1007.75 / 44.5
= 22.646067
= 22.64 m/s
Answer:
114.86%
Explanation:
In both cases, there is a vertical force equal to the sprinter's weight:
Fy = mg
When running in a circle, there is an additional centripetal force:
Fx = mv²/r
The net force is found with Pythagorean theorem:
F² = Fx² + Fy²
F² = (mv²/r)² + (mg)²
F² = m² ((v²/r)² + g²)
F = m √((v²/r)² + g²)
Compared to just the vertical force:
F / Fy
m √((v²/r)² + g²) / mg
√((v²/r)² + g²) / g
Given v = 12 m/s, r = 26 m, and g = 9.8 m/s²:
√((12²/26)² + 9.8²) / 9.8
1.1486
The force is about 114.86% greater (round as needed).
What happens when the light hits the glass depends on what it was in before it hit the glass.
WHILE it's in the glass, the speed of light doesn't change.
