Answer:
the number of grains in the ball is 274,848
Explanation:
Given that;
diameter = 0.5 mm
so radius r = 0.25 mm
first we determine the volume of the ball using the following equation;
V = 4/3×πr³
we substitute
V = 4/3×π(0.25)³
V = 0.06544 mm³
Now form table 1.1 "Grain sizes" a metal with grain size number of 12 has about 4,200,000 grains/mm³
so;
Number of grains N = 0.06544 × 4,200,000
N = 274,848 grains
Therefore, the number of grains in the ball is 274,848
Answer:
(a) W = 1329.5 J = 1.33 KJ
(b) ΔU = 24.27 KJ
Explanation:
(a)
Work done by the gas can be found by the following formula:
where,
W = Work = ?
P = constant pressure = (0.991 atm)() = 100413 Pa
ΔV = Change in Volume = 18.7 L - 5.46 L = (13.24 L)() = 0.01324 m³
Therefore,
W = (100413 Pa)(0.01324 m³)
<u>W = 1329.5 J = 1.33 KJ</u>
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(b)
Using the first law of thermodynamics:
ΔU = ΔQ - W (negative W for the work done by the system)
where,
ΔU = change in internal energy of the gas = ?
ΔQ = heat added to the system = 25.6 KJ
Therefore,
ΔU = 25.6 KJ - 1.33 KJ
<u>ΔU = 24.27 KJ</u>
Answer: A) Deceleration of the car is -6.6667 m/s² while it came to stop.
B) The total distance the car travels is 200 meter during the 10 s period.
Explanation:
Given Data
Initial velocity of the car () = 20.0 m/s
Final velocity of the car () = 0 m/s
Time (in motion) =7.00 s
Time (in rest) =3 s
To find - A) car's deceleration while it came to a stop
B) the total distance the car travels in 10 s
A) The formula to find the deceleration is
Deceleration = (( final velocity - initial velocity ) ÷ Time) (m/s²)
Deceleration = (() - (
)) ÷ time (m/s²)
Deceleration = ( 0.0 - 20 ) ÷ 3 (m/s²)
Deceleration = (- 20) ÷ 3 (m/s²)
Deceleration = - 6.6667 m/s²
(NOTE : Deceleration is the opposite of acceleration so the final result must have the negative sign)
The car's deceleration is - 6.6667 m/s² while it came to a stop
B) The formula to find the distance traveled by the car is
Distance traveled by the car is equals to the product of the speed and time
Distance = Speed × Time (meter)
Distance = 20.0 × 10
Distance = 200 meters
The total distance the car travels during the period of 10 s is 200 meters