The Science of Rockets

According to Newton's Third Law, if someone jumps off a skateboard, the skateboard will roll backwards because......

• The mass of the skateboard is the same as the mass of the person jumping off

• The pull of gravity on the person is the same as the skateboard, regardless of size

• The air resistance on the person is great and the friction on the skateboard its small

• for the force that sent the person forward, there is an equal force pushing back on the skateboard.

Pumping air into the rocket makes it go up into the sky. What will happen if more Aires pumped into it?

• It will go higher

• It will stop sooner

• It will get smaller

• It will bounce more

An image of a model rocket and forces is shown. Assuming the only two forces on the rocket are lift and gravity, which of the following combinations would result in the rocket moving upward?

• Lift = 5N / gravity =5 N

• Lift 3 N / gravity = 4 N

• Lift 5 N / gravity = 4 N

• Lift 4 N / gravity 4 N

The illustration represents the motion of a model rocket. How many seconds did it take for the rocket to reach its highest point?

• 2 seconds

• 5 seconds

• 8 seconds

• 10 seconds

An air rocket is launched several times and fro each launch the number of pumps was recorded as well as the height reached by the rocket. If the patter shown in the data continues, how many pumps would it take for the rocket to reach a height of 15 meters?

• 30 pumps

• 15 pumps

• 25 pumps

• 10 pumps

Students create balloon rockets by taping drinking straws to balloons and running a thick string through the straw. The ends of the string are held tightly apart. when the balloon is inflated and released, it moves along the string. What should the students do to change the amount of friction that slows to motion of the balloon rocket?

• Try different color balloons

• Use a different type of tape

• Replace the string with thin wire

• Hold the string ends closer together

Newtons first law of motion, applied to a book sitting on a table, would explain that the book will not move until which of the following conditions is met?

• Gravity on the book can be reduced to zero

• Unbalanced forces at on the book

• Balanced forces act on the book

• Friction being exerted on the book

A toy train engine rests motionless on a track. One student begins pushing the engine to the right with a force of 2 N. At the same time, another student begins pushing the engine to the left with a force of 5 N. Which of the following best describes the resulting motion of the engine?

• It travels left at a constant speed

• It travels left at an increasing speed

• it travels right at a constant speed

• It travels right at an increasing speed

Which of the following is the first challenge that had to be overcome by rockets in order for humans to explore space? First, rockets needed -

• a place in which the astronauts could sit

• a way to return to Earth's surface

• enough thrust to overcome Earth's gravity

• landing gear that worked on another planet

Jennifer and Marcos launch air rockets in their science class. air pressure from a hand pump caused the rockets to rise into the sky. What force causes them to return toward the ground?

• Wind pushing up

• Pull of Earth's gravity

• Heat from the sun

• Magnetic North Pole