Question 14
The sides of a cube are measured with calipers.
The measured length of each side is (30.0 ± 0.1) mm.
The measurements are used to calculate the volume of the
cube.
What is the percentage uncertainty in the calculated
value of the volume?
A 0.01%
B
0.3% C
1% D 3%
Reference: Past Exam Paper – June 2018 Paper 11 Q5
Solution:
Answer:
C.
Length L = (30.0 ± 0.1) mm
Volume V = L3
Volume V = 303
= 27 000 mm3
Since V = L3,
ΔV / V
= 3 × ΔL / L
Percentage uncertainty in
V = (3 × ΔL / L)
× 100%
Percentage uncertainty in
V = (3 × 0.1/30) × 100%
Percentage uncertainty in V = 1 %
Uh I think you did 14 wrong.
ReplyDeletewhat is wrong?
DeleteIt's just the answer at the end. It is supposed to be 1 % but you, by mistake have written .01%. -Thanks for the concept, helped me a lot
Deletethanks. it has been corrected
Delete9702 w18 qp11.The force resisting the motion of a car is proportional to the square of the car’s speed. The
ReplyDeletemagnitude of the force at a speed of 20.0 m s–1 is 800 N.
What useful output power is required from the car’s engine to maintain a steady speed of
40.0 m s–1?
go to
Deletehttp://physics-ref.blogspot.com/2019/06/the-force-resisting-motion-of-car-is.html
the length of a strip is measured by a metre scale as 3.4 cm if the same length is measured by a vernier calliper then reading is
ReplyDelete3.40 cm as a vernier can give a more precise value
Delete