Sandy is building a small toy car. he wants to use a balloon to power the toy car. he fills a balloon with air and then attaches a straw to the balloon. he tapes the balloon-straw combination to the car and then releases the end of the balloon.

the toy moves forward as the air from the balloon comes out the back of the straw. what can sandy do to make the toy car move faster?
a) use less air in the balloon.
b) blow up the balloon more.
c) use a longer straw.
d) use larger tires.

What can Sandy do to make the toy car move faster?

The Answer is B) Blow p the balloon more

Explanation:

A) Use less air in the balloon. Its wrong because what we need is to make the toy car move faster and if its source is the air inside the balloon, removing air will cause it to move less.

B) Blow up the balloon more. It is correct because if you blow up the balloon more, the air inside it escapes through the straw faster and will increase the speed of the toy car.

C) Use a longer straw. It is wrong because what we are looking for is to increase the speed of the toy car, and that is only achieved by reducing the weight of the toy car or increasing the force applied to its movement. The straw has nothing to do with it.

D) Use larger tires. It is wrong because using larger tires increases the weight of the toy car and as the air in the balloon remains the same there would be no changes in speed.

answer would be b, a tariffs main purpose is to protect domestic production and jobs.

the earth’s crust is broken into separate pieces called tectonic plates (fig. 7.14). recall that the crust is the solid, rocky, outer shell of the planet. it is composed of two distinctly different types of material: the less-dense continental crust and the more-dense oceanic crust. both types of crust rest atop solid, upper mantle material. the upper mantle, in turn, floats on a denser layer of lower mantle that is much like thick molten tar.

each tectonic plate is free-floating and can move independently. earthquakes and volcanoes are the direct result of the movement of tectonic plates at fault lines. the term fault is used to describe the boundary between tectonic plates. most of the earthquakes and volcanoes around the pacific ocean basin—a pattern known as the “ring of fire”—are due to the movement of tectonic plates in this region. other observable results of short-term plate movement include the gradual widening of the great rift lakes in eastern africa and the rising of the himalayan mountain range. the motion of plates can be described in four general patterns:

collision: when two continental plates are shoved together

subduction: when one plate plunges beneath another (fig. 7.15)

spreading: when two plates are pushed apart (fig. 7.15)

transform faulting: when two plates slide past each other (fig. 7.15)