An object with a mass of 2 kg is revolving around a point at a distance of 4 m. If the object is making revolutions at a frequency of 4 Hz, what is the centripetal force acting on the object?
1 Answer
Explanation:
The centripetal force is given in accordance with Newton's second law as:
F_c=ma_c where
m is the mass of the object anda_c is the centripetal acceleration experienced by the object
The centripetal acceleration is given by:
a_c=v^2/r
which is equivalent to
F_c=mromega^2 where
r is the radius andomega is the angular velocity of the object
The angular velocity can also be expressed as:
omega=2pif where
f is the frequency of the revolution
And so our final expression becomes:
color(blue)(F_c=mr(2pif)^2
We are given:
-
|->"m"=2"kg" -
|->"r"=4"m" -
|->f=4"s"^-1
Substituting these values into the equation we derived above:
F_c=(2"kg")(4"m")(2pi(4"s"^-1))^2
=5053.237"N"
~~5053N radially inward
This may also be expressed in scientific notation as