Answer:
Percent error = -22%
Explanation:
Given data:
Density of aluminium = 2.1,2.12 and 2.09 g/cm³
Accepted value of density of aluminium = 2.7 g.cm³
Percent error = ?
Solution:
First of all we will calculate the average of data measured by students.
Average value = 2.1 g/cm³ + 2.12 g/cm³+ 2.09 g/cm³ / 3
Average value = 6.31 g/cm³/ 3
Average value = 2.1 g/cm³
Now we will calculate the percent error.
Percent error = [ Measured value - accepted value / accepted value ]× 100
Percent error = [ 2.1 g/cm³ - 2.70 g/cm³ / 2.70 g/cm³ ]× 100
Percent error = [-0.6/2.70 g/cm³ ] × 100
Percent error = -0.22 × 100
Percent error = -22%
Answer:
P = 83.16 Watt
Explanation:
Given data:
Mass of box = 2 Kg
velocity of box = 29.7 m/s
Time = 21 sec
Power = ?
Solution:
Formula:
Power = work done/time
Now we will calculate the work done.
W = force × distance ...... (1)
d = speed /time
d = 29.7 m/s× 21 s
d = 623.7 m
Force:
acceleration = 29.7 m/s / 21 s
a = 1.4 m/s²
Force = m×a
Force = 2 kg×1.4 m/s²
Force = 2.8 N
Now we will put the values in equation 1.
W = F × d
W = 2.8 N ×623.7 m
W = 1746.36 Nm
Now for power:
P = W / time
P = 1746 Nm / 21 s
P = 83.16 Watt
A solution is a homogenous mixture meaning it has a uniform appearance throughout. (example: salt water)
heterogeneous mixture is visibly composed of different things. (example: chicken noodle soup)
You must add 7.5 pt of the 30 % sugar to the 5 % sugar to get a 20 % solution.
You can use a modified dilution formula to calculate the volume of 30 % sugar.
<em>V</em>_1×<em>C</em>_1 + <em>V</em>_2×<em>C</em>_2 = <em>V</em>_3×<em>C</em>_3
Let the volume of 30 % sugar = <em>x</em> pt. Then the volume of the final 20 % sugar = (5 + <em>x</em> ) pt
(<em>x</em> pt×30 % sugar) + (5 pt×5 % sugar) = (<em>x</em> + 5) pt × 20 % sugar
30<em>x</em> + 25 = 20x + 100
10<em>x</em> = 75
<em>x</em> = 75/10 = 7.5
