Day 1: Introduction and Energy
Name ________________
Speedboat Goal: Build a boat that travels the length of the trough in the shortest time. The time is measured
from when the bow crosses the starting line to when the bow crosses the finish line.
Restrictions:
 Maximum length: The boat (including motor and propellers) must fit lengthways into the box.
 The hull can be made from Styrofoam (provided) or any other material as long as they are NOT boat hulls.
 Standard motors are provided and must be used. You may use as many motors as you like.
 Propulsion is from blades pushing air not water. They must be handmade. Tongue depressors and Popsicle
sticks will be provided. Other materials may be used as long as they aren’t propellers.
 You supply the batteries and can use as many as you like.
 Hot glue, corks and dowelling are provided to attach propellers to motors.
1) The batteries, motors and propellers are used to get the boat moving quickly. You are transferring electrical
energy VIt into kinetic energy ½ mv2.
a) Explain clearly what each variable stands for and what unit it is measured in.
V
I
t
m
v
b) This equation suggests that your boat will go faster and faster during the race. If it runs for four times as
long, how much faster should it go? Explain your answer.
A) 16
B) 4
C) 2
D) 1.4
c) How can you increase the rate by which energy goes into the boat by your battery choice?
d) How can you increase the rate by which energy goes into the boat by your motor choice?
e) Explain why you want the boat to be as light as possible. Refer to the equations.
f) What is the density of Styrofoam? Show your steps.
g) What is the mass of each battery type?
h) What advantage do the 9-V batteries have over the AAA’s?
i)
What is the mass of each motor type?
j)
What is the smallest volume of Styrofoam that can just float the heaviest motor and two 9-V batteries?
k) You want to use more than this minimum amount of Styrofoam, why?
l)
Experiment with the materials. What else have you learnt that may help you in this contest?