Answer: Lightning is mostly light and electricity, this light that is hitting is going at a rate of 299,792.458 km per second (or 186,282 miles per second) this is so much compared to sound which only travels at about 761 mph (or approximately 332 meters per second). Fun fact: The lightening you are seeing is that coming back to the cloud because the process happens so fast.
Explanation:
Answer:
A. The athlete isn’t doing any work because he doesn’t move the weight.
Explanation:
We must remember the definition of work, which says that work is equal to the product of mass by the distance displaced. In this case, the athlete only does work when he lifts the weight from the ground to the point where he holds the weight suspended.
So when he's holding the weight, he doesn't do any work.
Answer:

Explanation:
Given:
- mass of vehicle,

- radius of curvature,

- coefficient of friction,

<u>During the turn to prevent the skidding of the vehicle its centripetal force must be equal to the opposite balancing frictional force:</u>

where:
coefficient of friction
normal reaction force due to weight of the car
velocity of the car

is the maximum velocity at which the vehicle can turn without skidding.