A 1500 kg car rounds a horizontal curve with a radius of 52 m at a speed of 12 m/s. what minimum coefficient of friction must ex
1 answer:
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Answer:
60000 J
Explanation:
Assuming the force is applied parallel to the displacement of the elephant, the work done to move it across the floor is
where
F = 2000 N is the force applied
d = 30 m is the displacement of the elephant
Substituting the numbers into the formula, we find
Answer:
electrons
Explanation:
The magnitude of the electric field outside an electrically charged sphere is given by the equation
where
k is the Coulomb's constant
Q is the charge stored on the sphere
r is the distance (from the centre of the sphere) at which the field is calculated
In this problem, the cloud is assumed to be a charged sphere, so we have:
is the maximum electric field strength tolerated by the air before breakdown occurs
is the radius of the sphere
Re-arranging the equation for Q, we find the maximum charge that can be stored on the cloud:
Assuming that the cloud is negatively charged, then
And since the charge of one electron is
The number of excess electrons on the cloud is