Answer:
2 revolutions.
Explanation:
We need to obtain the angular velocity when he is in the air.
The angular momentum is given by:
Because of angular momentum conservation L1=L2, so the final angular velocity is given by:
We need to calculate the time the skater is in the air, so we need to use the formula of parabolic motion:
so the time taken is 1.26s
the angular displacement is given by:
the number of revolutions is given by:
the skater execute two complete revolutions in the air.
To determine the distance of the light that has traveled given the time it takes to travel that distance, we need a relation that would relate time with distance. In any case, it would be the speed of the motion or specifically the speed of light that is travelling which is given as 3x10^8 meters per second. So, we simply multiply the time to the speed. Before doing so, we need to remember that the units should be homogeneous. We do as follows:
distance = 3x10^8 m/s ( 8.3 min ) ( 60 s / 1 min ) = 1.494x10^11 m
Since we are asked for the distance to be in kilometers, we convert
distance = 1.494x10^11 m ( 1 km / 1000 m) = 149400000 km
Football helmets that are made with padding are believed to have reduced head injuries especially when a player accidentally collides with an object. This is because the impact of the collision is decreased due to the padding that serves as a shock absorber.