Stuck on a physics problem. Help please? A uniform solid ball that has a mass of
ID: 2098091 • Letter: S
Question
Stuck on a physics problem. Help please?A uniform solid ball that has a mass of 21.8 g and a radius of 5.1 cm rests on a horizontal surface. A sharp force is applied to the ball in a horizontal direction 9.1 cm above the horizontal surface. During impact the force increases linearly from 0.0 N to 41.6 kN in 1.00 10-4 s, and then it decreases linearly to 0.0 N in 1.00 10-4 s.
(a) What is the speed of the ball just after impact?
(b) What is the angular speed of the ball after impact?
(c) What is the speed of the ball when it begins to roll without slipping?
(d) How far does the ball travel along the surface before it begins to roll without slipping? Assume that ?k = 0.50.
Stuck on a physics problem. Help please?
A uniform solid ball that has a mass of 21.8 g and a radius of 5.1 cm rests on a horizontal surface. A sharp force is applied to the ball in a horizontal direction 9.1 cm above the horizontal surface. During impact the force increases linearly from 0.0 N to 41.6 kN in 1.00 10-4 s, and then it decreases linearly to 0.0 N in 1.00 10-4 s.
(a) What is the speed of the ball just after impact?
(b) What is the angular speed of the ball after impact?
(c) What is the speed of the ball when it begins to roll without slipping?
(d) How far does the ball travel along the surface before it begins to roll without slipping? Assume that ?k = 0.50.
Explanation / Answer
(a)
mv=Fdt
avg force during interval dt=2x10^-4 s is
F=41.6/2=20.8 N
then
v=Fdt/m
v=20.8*2x10^-4/0.0218
v=0.19 m/s
b)
I?=mvd
?=mvd/I
I=2/5mr^2
?=5vd/(2r^2)
d=4 cm
?=5*0.19*0.04/(2*2.6x10^-3)
?=7.3 rad/s
c)
v=?r
v=7.3*0.051
v=0.37 m/s
d)
1/2mv^2=?kmgL
L=(1/2mv^2)/(?kmg)
L=(0.5*0.0218*0.0225)/(0.5*0.0218*9.8)
L=2.45x10^-3/0.106
L=0.023 m = 2.3 cm