Answer:
a. If c = 20 cm, then the mass of the brain is m = 5 g.
b. At c = 20 cm, the brain's mass is increasing at a rate of 15.75 g/cm.
Explanation:
From the equation
we have
a. for c = 20 cm
then the mass is m(20) = 5 g.
b. In order to find the rate of change, first we derivate
Evaluated at c = 20 cm, we have
So, at c = 20 cm, the mass of the brain is increasing at a rate of 15.75 g/cm.
At the point of maximum displacement (a), the elastic potential energy of the spring is maximum:
while the kinetic energy is zero, because at the maximum displacement the mass is stationary, so its velocity is zero:
And the total energy of the system is
Viceversa, when the mass reaches the equilibrium position, the elastic potential energy is zero because the displacement x is zero:
while the mass is moving at speed v, and therefore the kinetic energy is
And the total energy is
For the law of conservation of energy, the total energy must be conserved, therefore
. So we can write
that we can solve to find an expression for v:
Answer:
0.000001 kg
Explanation:
because 1 kg equal 1,000,000 milligrams
we take which equals 0.000001 kg
Answer:
Explanation:
Given
mass of book(m)=2.1 kg
height up to which book is lifted is (h)2.2 m
height of person
Potential energy of book relative to ground=mgh
(b)PE w.r.t to person head =mg(h-h0)
work done by person in lifting box 2.2 m w.r.t floor
Word done =Potential Energy of box relative to floor=45.2 J