Answer:
0.456033049
Explanation:
where N=mg hence
where m is mass of object, g is acceleration due to gravity whose value is taken as 
, 
is the coefficient of static friction and F is the applied force.
Making the subject we obtain
and substituting m for 38 Kg, g for and 170 N for F we obtain
Therefore, the coefficient of static friction is 0.456033049
Answer:
B will take 1.034 times the time of A from Boston to Hartford.
Explanation:
Let the distance from Boston to Hartford be S.
Person A drives at a constant speed of 55 mph for the entire trip,
Time taken by person A
Person B drives at 65 mph for half the distance and then drives 45 mph for the second half of the distance.
Time taken by person B
Ratio of time of arrival of B to A
B will take 1.034 times the time of A from Boston to Hartford.
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: B
Explanation: I said B because if you pull something back what is going to be more of a force pulling back or letting it go for a rubier band yes it will have more force if you let it go
<span>It is quite straightforward to convert an uncertainty to a percent uncertainty. We can divide the amount of uncertainty by the original amount and then multiply by 100%.
(2 m / 20,000,000 m) X 100% = 0.00001%
The percent uncertainty is 0.00001%.
The percent accuracy is the 100% - percent uncertainty.
The percent accuracy = 100% - 0.00001% = 99.99999%
The percent accuracy is 99.99999%.</span>
