Practice Questions Related to Word Problems
1. A train travels at constant velocity for 6 minutes and 10 seconds. During that time, it covers a distance of
740 m. Determine
a) the total time in seconds
b) average speed in m/s
c) average speed in km/hr
2. A car travels for 1 hours and 20 minutes and has an average speed of 90 km/hr. Determine the total distance
the car moves.
3. Super Spy Agent 002 (rival to 001) decides he must obtain the secret formula for a world famous cookie, to
impress his boss Z (knowing that Z loves baked goods). By obtaining the formula and baking the cookie for
Z, 002 hopes to be promoted to 001. While 002 is on route to the airport, his car (a Stealth) accelerates from
4 m/s to 75.6 km/hr in 5 seconds. Determine the average acceleration.
4. 002 steps on the plane for a flight from Toronto to CookieLand Canada, home of the best cookie making
factories in the world. The plane, initially moving with a velocity of 7.2 km/hr begins to accelerate and 4
seconds later covers a distance of 24 meters. Determine the acceleration of the plane. Determine the
velocity of the plane after 4 seconds.
5. While on the plane, 002 discovers that he boarded on the wrong flight and that it is heading in the opposite
direction. So he decides to jump off the plane with a parachute and his initial speed is 3 m/s [D]. Assume
his acceleration is -9.8 m/s2 [Up] and after he falls a distance of 52 m [D], determine his final velocity.
6. The fastest of all fishes is the sailfish. If a sailfish accelerates at a rate of 14 (km/hr)/a [fwd] for 4.7 s from
its initial velocity of 42 km/h [fwd], what is its final velocity?
7. An arrow strikes a target in an archery tournament. The arrow undergoes an average acceleration of 1.37
x103 m/s [W] in 3.12 x 10-2 s, the stops. Determine the velocity of the arrow when it hits the target.
8. A baseball travelling horizontally at 41 m/s [S] is hit by a baseball bat, causing its velocity to become 47
m/s [N]. The ball is in contact with the bat for 1.9 ms, and undergoes constant acceleration during this
interval. What is that acceleration?
9. A steel ball is thrown from the ledge of a tower so that it has an initial velocity of magnitude 15.0 m/s. The
ledge is 15.0 m above the ground. Air resistance is negligible.
a. What are the total flight time and the speed of impact at the ground if the initial velocity is downward?
10. A baseball pitcher throws a ball vertically upward and catches it at the same level 4.2 s later.
a. With what velocity did the pitcher throw the ball?
b. How high does the ball rise?
11. A hot air balloon is moving with a velocity of 2.1 m/s [up] when the balloonist drops a ballast (a large mass
used for height control) over the edge. The ballast hits the ground 3.8 s later.
12. Determine the constant acceleration needed for a bullet to reach a muzzle velocity of 4.0 x 102 m/s [fwd],
provided friction is zero and the muzzle is 0.80 m long.
Answers on next page!!!!
Answers for Practice Questions Related to Word Problems
1.
a)
b)
c)
6 minutes is 360 seconds therefore 6 minutes 10 seconds is 370 seconds
v = 740/370 = 2 m/s
v = 2 x 3.6 = 7.2 km/hr
2.
1 hour and 20 minutes is NOT 1.2 hours. Instead, 20 minutes represents 0.33 hours (20/60)
therefore
1 hour and 20 minutes is
1.33 hours
The distance traveled is
90 x 1.33 = 120 km.
3.
Initial speed is
4 m/s
Final velocity is
Final velocity is
75.6 km/hr, however convert this to m/s (75.6 / 3.6 = 21 m/s)
21 m/s
The time is
5 seconds
therefore
a = (21 – 4)/5 = 17/5 = 3.4 m/s2
4.
distance is
24 m
time is
4 seconds
Initial velocity is
7.2 km/hr = 2 m/s
Δd = v1Δt + ½ a Δt2
acceleration is
2 m/s2
5.
Initial velocity is
3 m/s [Down]
Acceleration is
-9.8 m/s2 [Up] = 9.8 m/s2 [Down]
Displacement is
52 m [Down]
When solving problems that have vectors with multiple direction (ie up and down), choose to either represent
all the vectors as either having a down or up direction. For this example, we will choose the down vector for
acceleration so that the vectors are consistent.
Solving for final velocity
v22- v12 = 2aΔd
Final velocity is
32.1 m/s [Down]
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