Answer: 14.16
Explanation:
Given
d = 38cm
r = d/2 = 38/2 = 19cm = 0.19m
K.E = 510J
m = 10kg
I = 1/2mr²
I = 1/2*10*0.19²
I = 0.18kgm²
When it has 510J of Kinetic Energy then,
510J = 1/2Iω²
ω² = 1020/I
ω² = 1020/0.18
ω² = 5666.67
ω = √5666.67 = 75.28 rad/s
Velocity is the block, v = ωr
V = 75.28 * 0.19
V = 14.30m/s
The "effective mass" M of the system is
M = (14.0 + ½*10.0) kg = 19.0 kg
The motive force would be
F = ma
F = 14 * 9.8
F = 137.2N
so that the acceleration would be
a = F/m
a = 137.2/19
a = 7.22m/s²
Finally, using equation of motion.
V² = u² + 2as
14.3² = 0 + 2*7.22*s
204.49 = 14.44s
s = 204.49/14.44
s = 14.16m
The answer is "friction and air resistance" gravity does some of the work by keeping the object from floating away, but friction and air resistance does the biggest part. Friction is how rough the ground it meaning on tile, dirt, grass, etc... that would slow down the object and air resistance is the gravity pushing on the object also making it stop.
Hope this helps!
Yes, that's correct. That's a big part of the reason why
the soap floats in water and the sponge sinks in it.
Answer:
I = M R^2 is the moment of inertia about a point that is a distance R from the center of mass (uniform distributed mass).
The moment of inertia about the center of a sphere is 2 / 5 M R^2.
By the parallel axis theorem the moment of inertia about a point on the rim of the sphere is I = 2/5 M R^2 + M R^2 = 7/5 M R^2
I = 7/5 * 20 kg * .2^2 m = 1.12 kg m^2