A small block of mass m = 270 g is released from rest at point (A) along the hor
ID: 1903458 • Letter: A
Question
A small block of mass m = 270 g is released from rest at point (A) along the horizontal diameter on the inside of a frictionless, hemispherical bowl of radius R = 31.5 cm as shown in the figure below.
(a) Calculate the gravitational potential energy of the block-Earth system when the block is at point (A) relative to point (B). _______________J ???
(b) Calculate the kinetic energy of the block at point (B) ________________J ???
(c) Calculate its speed at point (B) ______________m/s ???
(d) Calculate its kinetic energy when the block is at point (C) ___________J ???
(e) Calculate the potential energy when the block is at point (C) ___________J ???
Explanation / Answer
a.)
at point B, assuming potential energy is zero.
so gravitation potential energy at point a relative to point b is mgR.
= 0.27*9.8*0.315
=0.833 J
c.)
0+mgR = 1/2 mvb^2 + 0
vb = sqrt(2gR)
vb = 2.48 m/s
b.)
1/2 mvb^2
=0.5*0.27*2.48^2
=0.83J
e.)
potential enery = mg(2R/3)
= 0.27*9.8*0.67*0.315
=0.56 J
d.)
Ke = 0.5(0.27*2.48^2) - 0.56 = 0.27J