A ball of mass 0.35 kg hangs straight down on a string of length 13 cm. It is then swung upward, keeping the string taut, until
the string makes an angle of 70° with respect to the vertical. Find the change in the gravitational potential energy of the Earth-ball system.
1 answer:
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Answer:
The maximum speed at which the car can safety travel around the track is 18.6m/s.
Explanation:
Since the car is in circular motion, there has to be a centripetal force . In this case, the only force that applies for that is the static frictional force
between the tires and the track. Then, we can write that:
And since and
, we have:
Now, if we write the vertical equation of motion of the car (in which there are only the weight and the normal force), we obtain:
Substituting this expression for and solving for
, we get:
Finally, plugging in the given values for the coefficient of friction and the radius of the track, we have:
It means that in its maximum value, the speed of the car is equal to 18.6m/s.