Answer:
angular acceleration is -0.2063 rad/s²
Explanation:
Given data
mass m = 95.2 kg
radius r = 0.399 m
turning ω = 93 rpm
radial force N = 19.6 N
kinetic coefficient of friction μ = 0.2
to find out
angular acceleration
solution
we know frictional force that is = radial force × kinetic coefficient of friction
frictional force = 19.6 × 0.2
frictional force = 3.92 N
and
we know moment of inertia that is
γ = I ×α = frictional force × r
so
γ = 1/2 mr²α
α = -2f /mr
α = -2(3.92) /95.2 (0.399)
α = - 7.84 / 37.9848 = -0.2063
so angular acceleration is -0.2063 rad/s²
Answer:
95 %
99.7 %
Explanation:
= 166 cm = Mean
= 5 cm = Standard deviation
a) 156 cm and 176 cm
From the empirical rule 95% of all values are within 2 standard deviation of the mean, so about 95% of men are between 156 cm and 176 cm.
b) 151 cm and 181 cm
The empirical rule tells us that about 99.7% of all values are within 3 standard deviations of the mean, so about 99.7% of men are between 151 cm and 181 cm.
The correct statements are:
B. a small rock sitting on top of a big rock
As the rock is at a height with respect to ground it has potential Energy
and
C. a stretched rubber band
A stretched rubber band has elastic potential energy
The others are actually moving and hence would consist of Kinetic energy. Potential energy is stored in objects that do not move and are stationary.
They are poor conductors because they keep the heat trapped in one spot, while other materials like metal let the heat go through itself.
