Athabasca University PHYS 204 Assignment 1
Assignment 1
The ten questions below cover Units 1–4 and each carries equal weight. You are expected to
solve all questions in detail and submit by uploading to the appropriate drop box. Scanned copy
of your handwritten solutions should be acceptable.
A 1.0 ft × 5.0 ft sheet of aluminum foil has a mass of 16 g. What is the thickness of the sheet?
(Density of aluminum = 2,700 kg/m3)
12 in. 2 2.54 cm 2 1 m. 2
𝐂𝐨𝐧𝐯𝐞𝐫𝐬𝐢𝐨𝐧 𝐨𝐟 𝐟𝐭 𝐭𝐨 𝐤𝐠: 5.0 ft 2 × (
) ×( ) ×( ) = 0.4645 m2
1 ft. 1 in. 100 cm.
m kg
𝐅𝐨𝐫𝐦𝐮𝐥𝐚 𝐟𝐨𝐫 𝐝𝐞𝐧𝐬𝐢𝐭𝐲: ρ ≡ = 3
V m
Finding the 3rd dimension of the sheet:
kg 0.016 kg Al.
2,700 3
Al. =
m (0.4645 m2 )(x m)
(2,700)(0.4645 m2 )(x m) = (0.016 )
x = 0.0000127576 m.
The thickness of the Aluminum sheet is 1.3 × 10−5 m.
1. A 420 g soccer ball travelling at 23 m/s hits the goal post and rebounds at 18 m/s. If the ball
is in contact with the post for 3.3 ms, what is the average acceleration of the ball during this
time interval?
v1 = 23 m/s
v2 = −18 m/s
ax = ?
t = 0.0033 s
v2 = v1 + a x t
−18 = 23 + a x (0.0033)
a x = −12,424.24 m/s2
The average acceleration is −1.2 x 104 m/s2.
2. An object is shot vertically upward and has a speed of 12.0 m/s when it reaches one fifth of
its maximum height.
a. What is the initial speed of the object?
vtop,max = 0 m/s
vi = ? ? m/s
Physics 204: Physics for Scientists and Engineers I 1
Assignment 1
The ten questions below cover Units 1–4 and each carries equal weight. You are expected to
solve all questions in detail and submit by uploading to the appropriate drop box. Scanned copy
of your handwritten solutions should be acceptable.
A 1.0 ft × 5.0 ft sheet of aluminum foil has a mass of 16 g. What is the thickness of the sheet?
(Density of aluminum = 2,700 kg/m3)
12 in. 2 2.54 cm 2 1 m. 2
𝐂𝐨𝐧𝐯𝐞𝐫𝐬𝐢𝐨𝐧 𝐨𝐟 𝐟𝐭 𝐭𝐨 𝐤𝐠: 5.0 ft 2 × (
) ×( ) ×( ) = 0.4645 m2
1 ft. 1 in. 100 cm.
m kg
𝐅𝐨𝐫𝐦𝐮𝐥𝐚 𝐟𝐨𝐫 𝐝𝐞𝐧𝐬𝐢𝐭𝐲: ρ ≡ = 3
V m
Finding the 3rd dimension of the sheet:
kg 0.016 kg Al.
2,700 3
Al. =
m (0.4645 m2 )(x m)
(2,700)(0.4645 m2 )(x m) = (0.016 )
x = 0.0000127576 m.
The thickness of the Aluminum sheet is 1.3 × 10−5 m.
1. A 420 g soccer ball travelling at 23 m/s hits the goal post and rebounds at 18 m/s. If the ball
is in contact with the post for 3.3 ms, what is the average acceleration of the ball during this
time interval?
v1 = 23 m/s
v2 = −18 m/s
ax = ?
t = 0.0033 s
v2 = v1 + a x t
−18 = 23 + a x (0.0033)
a x = −12,424.24 m/s2
The average acceleration is −1.2 x 104 m/s2.
2. An object is shot vertically upward and has a speed of 12.0 m/s when it reaches one fifth of
its maximum height.
a. What is the initial speed of the object?
vtop,max = 0 m/s
vi = ? ? m/s
Physics 204: Physics for Scientists and Engineers I 1
