SPH3U
Worksheet 1.5- Acceleration Due to Gravity
Date:
Answer the following questions on a separate sheet. Please show all your work; including
units, significant direction and direction. Use g = 9.80 m/s2 [down]
1. Text: p 38 #1
p49 #9
2. What velocity does a freely falling object reach after 4.0 s if it starts from rest?
3. James throws a rock into a deep well with a velocity of 10.0 m/s [down]. What is the
velocity of the rock 2.5 s later?
4. A ball was thrown straight up at 29 m/s then caught at the same place it was released.
How many seconds was it in the air?
5. Jason throws a baseball into a deep well at 4.0 m/s [down]. If it hits the water in 2.0 s,
a) How far below the ground is the water’s surface?
b) What is the ball’s average velocity?
c) How soon after it is thrown does the ball actually acquire the velocity calculated in (b)?
d) What is the velocity of ball when it hits the water?
6. A tourist drops a rock from rest from a guardrail at an observatory point overlooking a
valley. Calculate the velocity of the rock at the following times: a) 2.0 s
b) 6.0 s
7.
Determine the displacement for the rock in question 6 at:
a) 2.0 s
b) 6.0 s
8. Melissa uses a slingshot to fire a stone straight up at 24 m/s.
a) What is the stone’s velocity 3.0 s later?
b) What is the displacement 3.0 s after it was fired?
9. A prankster drops a water-filled balloon from the balcony of a high-rise. How long does it
take for the balloon to fall 44.1 m?
10. Suppose the tourist in question 5 threw the rock with an initial velocity of 8.0 m/s [down].
a) Determine the velocity of the rock at 2.0 s and 6.0 s.
b) Determine the displacement of the rock at 2.0 s and 6.0 s.
11. The acceleration due to gravity on the moon is about 1.6 m/s2. How long would it take for a
2.0 kg hammer to hit the surface of the moon, if it was dropped from a height of 1.8 m?
12. The CN Tower is 533.33 m high.
a) How long would it take a rock, dropped from the top to reach the ground?
b) How fast would the rock be moving as it hits the ground (in m/s and km/h)?
c) Would the rock actually reach the speed calculated in (b)? Why or why not?
13. A stone is thrown straight up. To reach a maximum height of 5.05 m above its release
point, what must its initial speed be in m/s?
14. A stone is thrown straight up at 6.98 m/s. What is the stone's acceleration in m/s/s at the
top of its rise?
Answers:
2) 39 m/s [d]
3) 35 m/s [d]
4) 5.92 s
5) (a) 28 m [d] (b) 14 m/s [d] (c) 1.0 s (d) 24 m/s [d]
6) (a) 2.0x101 m/s [d] (b) 59 m/s [d]
7) (a) 2.0x101 m [d] (b) 1.8x102 m [d]
8) 5.4 m/s [d]; 28 m [u]
9) 3.0 s
10) (a) 28 m/s [d]; 36 m [d] (b) 67 m/s [d]; 2.3x102 m [d]
11) 1.5 s
12) (a) 1.0x101 s (b) 1.0x102 m/s [d] or 360 km/h [d]
13) 9.95 m/s
14) 9.80 m/s2 [d]