Answer:
Explanation:
a )
change in the gravitational potential energy of the bear-Earth system during the slide = mgh
= 45 x 9.8 x 11
= 4851 J
b )
kinetic energy of bear just before hitting the ground
= 1/2 m v²
= .5 x 45 x 5.8²
= 756.9 J
c ) If the average frictional force that acts on the sliding bear be F
negative work done by friction
= F x 11 J
then ,
4851 J - F x 11 = 756.9 J
F x 11 = 4851 J - 756.9 J
= 4094.1 J
F = 4094.1 / 11
= 372.2 N
Answer:
what.....................
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The tensile stress of the wire supporting 2 kg mass is determined as 6.1 x 10⁷ N/m².
<h3>
Tensile stress of the wire</h3>
The tensile stress of the wire is calculated as follows;
σ = F/A
where;
A = πr² = πD²/4
where;
A = π x (0.64 x 10⁻³)²/4
A = 3.22 x 10⁻⁷ m²
σ = F/A = (mg)/A = (2 x 9.8)/( 3.22 x 10⁻⁷)
σ = 6.1 x 10⁷ N/m²
Learn more about tensile stress here: brainly.com/question/25748369
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Answer: c
Explanation: because if it increases then it gets hotter
if it decreases then its getting colder.