The change in temperature, (2) the mass of the system, and (3) the substance and phase of the substance.
Answer:
102 dB
Explanation:
Intensity level is given by:
Given:
rod of circular cross section is subjected to uniaxial tension.
Length, L=1500 mm
radius, r = 10 mm
E=2*10^5 N/mm^2
Force, F=20 kN = 20,000 N
[note: newton (unit) in abbreviation is written in upper case, as in N ]
From given above, area of cross section = π r^2 = 100 π =314 mm^2
(i) Stress,
σ
=force/area
= 20000 N / 314 mm^2
= 6366.2 N/mm^2
= 6370 N/mm^2 (to 3 significant figures)
(ii) Strain
ε
= ratio of extension / original length
= σ / E
= 6366.2 /(2*10^5)
= 0.03183
= 0.0318 (to three significant figures)
(iii) elongation
= ε * L
= 0.03183*1500 mm
= 47.746 mm
= 47.7 mm (to three significant figures)
Answer:
2.5 x 10⁷ J
Explanation:
F = thrust of the engine = 2.3 x 10⁵ N
d = distance traveled = 87 m
Work done by the engine is given as
W = F d = (2.3 x 10⁵) (87) = 200.1 x 10⁵ J
W' = Net work done
W'' = work done by catapult
KE₀ = initial kinetic energy = 0 J
KE = final kinetic energy = 4.5 x 10⁷ J
Net work done is given as
W' = KE - KE₀
W' = 4.5 x 10⁷ J
We know that
W' = W + W''
4.5 x 10⁷ = 2.001 x 10⁷ + W''
W'' = 2.5 x 10⁷ J
