Balanced and Unbalanced Forces
What are balanced forces?
Forces that are equal in size but opposite in direction, resulting in no change in motion
What determines the strength of the gravitational force between two objects?
The masses of the objects and the distance between them.
What is friction?
A force that opposes the motion of two surfaces in contact.
What is gravity?
A force that attracts two bodies toward each other, depending on their masses and the distance between them.
What is the difference between mass and weight?
Mass is the amount of matter in an object, while weight is the force of gravity acting on that mass.
How do balanced forces affect an object's motion?
They do not change the motion of the object; it remains at rest or continues to move at a constant speed.
What is the formula for gravitational force?
F=Gr2m1m2, where GG is the gravitational constant.
Name the four types of friction.
Static, sliding, rolling, and fluid friction.
Who formulated the law of universal gravitation?
Sir Isaac Newton
How is weight calculated?
Weight is calculated using the formula W=mgW=mg, where mm is mass and gg is the acceleration due to gravity.
What are unbalanced forces?
Forces that are not equal in size or opposite in direction, resulting in a change in motion.
How does gravitational force change with distance?
It decreases with the square of the distance between the centers of the two objects.
How does friction affect motion?
It slows down or stops the motion of an object.
How does gravity affect objects on Earth?
It gives objects weight and causes them to fall toward the ground.
If an object has a mass of 10 kg, what is its weight on Earth?
Daily Double:
W=10kg×9.8m/s2=98N.
How do unbalanced forces affect the motion of an object?
They cause the object to accelerate, change direction, or change speed.
What role does gravitational force play in the orbits of planets?
Gravitational force keeps planets in orbit around the Sun.
What factors affect the amount of friction between two surfaces?
The types of surfaces in contact and the force pressing them together.
Describe how gravity varies with distance from the Earth.
Gravity decreases as the distance from the Earth's center increases.
How does mass change when an object goes to the Moon?
The mass stays the same, but the weight decreases due to lower gravity on the Moon.
What happens to an object when unbalanced forces are applied?
The object will start to move, stop moving, or change its velocity.
Describe how gravitational force affects tides on Earth.
The gravitational pull of the Moon and the Sun causes the rise and fall of ocean tides.
Explain how friction can be both beneficial and harmful.
Friction is beneficial for walking and driving but can cause wear and tear on machines.
What is the acceleration due to gravity on Earth?
Daily Double:
Approximately 9.8 m/s29.8m/s2.
Explain why astronauts feel weightless in space.
They are in free fall around the Earth, which creates the sensation of weightlessness.