Science Chap13 Interactive Reader
What is the weight of the astronaut on Earth? What is the weight of the astronaut on the moon?
1,588 N on Earth; 271 N on the moon
An astronaut visits Planet X. Planet X has the same radius as Earth but has twice the mass of Earth. Fill in the table below to show the astronaut's mass and weight on Planet X. (Hint: Newton's law of universal gravitation says that when the mass of one object doubles, the force due to gravity also doubles.)
80 kg; 1,568 N
What two characteristics affect gravity?
As the distance between two objects increases, the gravitational force decreases. As the distance between two objects decreases, the gravitational force increases.
Is the gravitational force greater between objects with small masses or objects with large masses?
Gravitational force is greater between objects with large masses.
What forces act on a framed picture on a shelf?
Gravity pulls down, and the shelf pushes up.
Describe two things you can do to increase the acceleration of an object.
Increase the force on the object. Decrease the mass of the object.
What determines the gravitational force between objects?
It is influenced by the masses of objects and the distance between them.
A spacecraft is moving toward Mars. Its rocket engines are turned off. As the spacecraft nears Mars, what will happen to the pull of the planet's gravity?
It will get larger.
How is mass different from weight?
Mass is the amount of matter in an object, but weight is the amount of gravitational force on an object.
What are the action and reaction forces when you kick a soccer ball?
The action force is the push of my foot on the ball. The reaction force is the ball pushing back on my foot.
Describe how weight and mass of an astronaut are different on Earth and on the moon.
The astronaut has the same mass on Earth and on the moon, but the astronaut has a greater weight on Earth than on the moon. This is because the gravitational force is less on the moon than on Earth because the moon has less mass than the Earth.
Each of the spheres shown below is made of iron. Circle the pair of spheres that would have the greatest gravitational force between them. Below the spheres, explain the reason for your choice.
The first pair should be circled. The reason is that the spheres are the largest pair of masses separated by the smallest distance.
When the forces on an object are balanced, describe the motion of the object.
The motion will not change. An object at rest will stay at rest. An object with a constant velocity will continue moving at constant velocity.
Why can't you see two soccer bails attracting each other?
Their masses are small, so they don't have much gravity.
What would happen if there were no friction between a rolling ball and the ground?
Without friction, the ball would continue to roll at the same speed, assuming the surface stayed level.
gravity
a force of attraction between objects that is due to their masses
mass
a measure of the amount of matter in an object
weight
a measure of the gravitational force exerted on an object; its value can change with the location of the object in the universe
Why does the moon revolve around Earth?
because of the gravitational pull between Earth and the moon
What is gravity?
force of attraction between objects due to their masses
Fill In Complete the Concept Map. Use the following words to fill in the blank ovals: acceleration, inertia, friction, force.
from left to right: force, friction, acceleration, inertia
Use the diagram to describe the affect of distance on gravitational force.
mass and distance
What two things determine gravitational force?
masses of objects, distance between objects
maintain
to keep the same