Answer:
Angular speed will reach 6.833rad/s before the coin starts slipping
Explanation:
There is no question but I'll asume the common one: Calculate the speed of the turntable before the coin starts slipping.
With a sum of forces:
At this point, friction force is maximum, so:
Solving for V:
V=1.025 m/s
The angular speed of the turntable will be:
ω = V/R = 6.833 rad/s This is the maximum speed it can reach before the coin starts slipping.
Answer:
Under assumption that all food energy that needs the horse is transformed into work, then the horse needs approximately 3 megajoules of food energy to work for 1 hour.
Explanation:
Since horse is working steadily, the power experimented by the horse (), measured in watts, is at constant rate. Then, the work needed by the horse (
), measured in joules, is equal to that power multiplied by time (
), measured in seconds. That is:
(1)
If we know that and
, then the work needed for the horse is:
Under assumption that all food energy that needs the horse is transformed into work, then the horse needs approximately 3 megajoules of food energy to work for 1 hour.
