earthscience u2

A wrecking ball has a mass of 650 kg. It swings from a cable that is 21 m long. The centripetal force on the ball is 56 N. What is the tangential speed of the wrecking ball? 1.3 m/s 1.8 m/s 46 m/s 870 m/s

1.3 m/s

The tip of a pinwheel is 0.24 m from the center. The pinwheel spins 5 times each second. What is the tangential speed of the tip of the pinwheel? 0.30 m/s 1.2 m/s 1.5 m/s 7.5 m/s

7.5 m/s

The edge of a flying disc with a radius of 0.13 m spins with a tangential speed of 3.3 m/s. The centripetal acceleration of the edge of the disc is ____m/s

84

The tip of a fan blade is 0.61 m from the center of the fan. The fan turns at a constant speed and completes 2 rotations every 1.0 s. What is the centripetal acceleration of the tip of the fan blade? 6.0 m/s2 48 m/s2 53 m/s2 96 m/s2

96 m/s2

Why do lunar and solar eclipses not happen every month? Eclipses only occur during full and new moons. Earth rotates around its axis faster than the moon. The moon and Earth only travel through the penumbras. The moon's axis does not always align with Earth's shadow.

The moon's axis does not always align with Earth's shadow.

Which factor affects the force of gravity between objects? Check all that apply. direction distance mass shape time

distance mass

During which moon phase do spring tides occur? new moon and full moon first quarter and third quarter waxing gibbous and waning gibbous waxing crescent and waning crescent

new moon and full moon

Which object would be considered to be in free fall? one that experiences both friction and centripetal force one that is truly weightless one that is slowed down by air resistance one with only gravity acting upon it

one with only gravity acting upon it

How often do spring and neap tides occur? twice a day twice a month every 27.3 days every 24 hours

twice a month

Which equation is used to calculate the weight of an object on a planet? w = mg w = mG w = m/g w = m/G

w = mg

During which phase does Earth see more than half of the moon's surface? first quarter third quarter waxing gibbous waning crescent

waxing gibbous

What is the downward pull on an object due to gravity? mass weight acceleration velocity

weight

When is an object moving in uniform circular motion? when it speeds up around a curve when its tangential speed is constant when it has no net force acting on it when its acceleration is tangent to a circle

when its tangential speed is constant

The orbital period of an object is 2 × 107 s and its total radius is 4 × 1010 m. The tangential speed of the satellite, written in standard notation, is___ m/s.

12560

The gravitational force between Pluto and Charon is 3.61 × 1018 N. Pluto has a mass of 1.3 × 1022 kg, which is only slightly greater than Charon's mass of 1.6 × 1021 kg. How far apart are Pluto and Charon? 2.0 × 107 m 2.4 × 1012 m 3.8 × 1014 m 5.8 × 1024 m

2.0 × 107 m

Which situation during a basketball game involves centripetal acceleration? The official tosses the ball up for the opening tip-off. A player passes the ball to another player. The basketball bounces off the backboard. A player spins a basketball on his finger.

A player spins a basketball on his finger.

Which statement best explains why objects are pulled toward Earth's center? Earth has a magnetic force that is strongest at its core. Earth has a much greater mass than objects on its surface. The weight of the atmosphere pushes objects toward Earth's surface. The strength of the Sun's gravity pushes down on objects at Earth's surface.

Earth has a much greater mass than objects on its surface.

What must be true of a force that causes an object to move in a circular motion? It acts parallel to the velocity and is directed toward the center of the circle. It acts parallel to the velocity and is directed away from the center of the circle. It acts perpendicular to the velocity and is directed toward the center of the circle. It acts perpendicular to the velocity and is directed away from the center of the circle.

It acts perpendicular to the velocity and is directed toward the center of the circle.

How is the gravitational force related to the distance between two objects? It is directly proportional to the square of the distance. It is inversely proportional to the square of the distance. It is directly proportional to the distance. It is inversely proportional to the distance.

It is inversely proportional to the square of the distance.

Two satellites, X and Y, are orbiting Earth. Satellite X is 1.2 × 106 m from Earth, and Satellite Y is 1.9 × 105 m from Earth. Which best compares the satellites? Satellite X has a greater period and a faster tangential speed than Satellite Y. Satellite X has a greater period and a slower tangential speed than Satellite Y. Satellite X has a shorter period and a faster tangential speed than Satellite Y. Satellite X has a shorter period and a slower tangential speed than Satellite Y.

Satellite X has a greater period and a slower tangential speed than Satellite Y.

A group of scientists is trying to launch an object into orbit, and the object is traveling at 6500 m/s. Which best explains why the object will not successfully orbit Earth? There is not enough air resistance to keep the object moving. There is not enough friction to keep the object moving. The object is not traveling fast enough to match Earth's curvature. The object is traveling too fast to match Earth's curvature.

The object is not traveling fast enough to match Earth's curvature.

Lucia wants to change the motion map shown so that it shows uniform circular motion. An illustration of a circle with four black dots on the top, bottom, left and right of the circle. Each dot has a vector toward the center of the circle and a vector tangent to the circle in a counterclockwise direction. What change should Lucia make? a: She should change the length of each vector that is tangent to the circle so that it is the same as the vector pointing toward the center at that point. b: She should change the direction of the vectors that are toward the center of the circle so that each points tangent to the circle opposite the existing tangent vectors. c: She should change the direction of the vectors that are toward the center of the circle so that each points away from the center of the circle. d: She should change the lengths of the vectors that point toward the center so that each is the same length.

d: She should change the lengths of the vectors that point toward the center so that each is the same length.

As a truck rounds a curve, a box in the bed of the truck slides to the side farthest from the center of the curve. This movement of the box is a result of ._____

inertia

Which feature of an object affects its weight? Check all that apply. mass of the object shape of the object location of the object how much energy the object has how much force Earth exerts on the object

mass of the object location of the object how much force Earth exerts on the object

The cycle of day and night is a result of Earth's spinning on its axis, which is Earth's ____

rotation

Which movement causes day and night on Earth? rotation of Earth revolution of Earth around the Sun Earth's elliptical orbit in space moon's orbit around Earth

rotation of Earth

Which statement explains how gravity and inertia work together? They change the motion of objects. They take turns working on objects. They keep all objects moving at the same speed. They prevent objects from moving in a circular motion.

They change the motion of objects.

The universal law of gravitation states that the force of attraction between two objects depends on which quantities? the masses of the objects and their densities the distance between the objects and their shapes the densities of the objects and their shapes the masses of the objects and the distance between them

the masses of the objects and the distance between them

A child on a spinning playground ride is 0.36 m from the center of the ride. The centripetal force on the child is 19 N. What is the mass of the child if the child has a tangential speed of 0.54 m/s? 3.7 kg 13 kg 23 kg 79 kg

23 kg

A spinning top rotates so that its edge turns at a constant speed of 0.63 m/s. If the top has a radius of 0.10 m, what is the centripetal acceleration of the edge of the top? 0.016 m/s2 0.73 m/s2 4.0 m/s2 6.3 m/s2

4.0 m/s2

The mass of the Sun is 1.99 × 1030 kg. Jupiter is 7.79 × 108 km away from the Sun and has a mass of 1.90 × 1027 kg. The gravitational force between the Sun and Jupiter to three significant figures is __ × 1023 N.

4.16

The gravitational force between two objects is 2400 N. What will be the gravitational force between the objects if the mass of one object is doubled? 600 N 1200 N 4800 N 9600 N

4800 N

Julius competes in the hammer throw event. The hammer has a mass of 7.26 kg and is 1.215 m long. What is the centripetal force on the hammer when it has a tangential speed of 31.95 m/s? The answer is rounded off to the nearest whole number. 190 N 840 N 1,400 N 6,100 N

6,100 N

The acceleration due to gravity on Jupiter is 23.1 m/s2, which is about twice the acceleration due to gravity on Neptune. Which statement accurately compares the weight of an object on these two planets? An object weighs about one-fourth as much on Jupiter as on Neptune. An object weighs about one-half as much on Jupiter as on Neptune. An object weighs about two times as much on Jupiter as on Neptune. An object weighs about four times as much on Jupiter as on Neptune.

An object weighs about two times as much on Jupiter as on Neptune.

How do inertia and centripetal force combine to keep an object moving in circular motion? Centripetal force acts toward the center of the circle to overcome inertia, which acts away from the center. Inertia acts toward the center of the circle to overcome centripetal force, which acts away from the center. Centripetal force acts toward the center of the circle, and inertia keeps the object moving forward. Inertia acts toward the center of the circle, and centripetal force keeps the object moving forward.

Centripetal force acts toward the center of the circle, and inertia keeps the object moving forward.

Dao makes a table to identify the variables used in the equations for centripetal acceleration. A 2 column 5 rows. The first column is labeled Variable with entries a Subscript c Baseline, T, r, v. The second column is labeled Quantity with entries blank, X, blank, Y. What quantities belong in cells X and Y? A: X: centripetal acceleration Y: period B: X: tangential speed Y: radius C: X: radius Y: centripetal acceleration D: X: period Y: tangential speed

D: X: period Y: tangential speed

Which statement describes gravity? Check all that apply. There is no defined unit of measurement for gravity. Gravity is the force that pulls objects toward Earth's center. Objects that have a small mass will have no gravitational pull. Gravitational pull between two objects increases as the mass of one increases. Gravitational pull decreases when the distance between two objects increases.

Gravity is the force that pulls objects toward Earth's center. Gravitational pull between two objects increases as the mass of one increases. Gravitational pull decreases when the distance between two objects increases.

Which statement explains how weight is different from mass? Mass is a varying property. Mass is measured in newtons. Weight is always greater than mass. Weight is a measure of gravitational pull.

Weight is a measure of gravitational pull.

The track of a roller coaster is shown below. An illustration of a roller coaster track with a first hill, just after the hill is a level section that dips down lower before going back up to a level lower than the original hill and levels off. There are 4 labeled points, W halfway up the first hill, X on the first level section, Y in the next dip and Z on the last level section. At which point will the riders experience centripetal acceleration? W X Y Z

Y

Enrique is given information about a satellite orbiting Earth. r = 3.8 × 108 m T = 18 days In order to calculate the tangential speed of the satellite, what should Enrique do first? convert the radius to kilometers convert the orbital period to seconds find the square root of the radius find the square root of the orbital period

convert the orbital period to seconds

In which direction does the Sun appear to move across the sky? from west to east from east to west from north to south from south to north

from east to west

During which phase of the moon does a lunar eclipse occur? full moon third quarter waxing gibbous waning crescent

full moon

What is the only force acting on an object orbiting Earth? air resistance friction inertia gravity

gravity

As the distance between a satellite in a circular orbit and the central object increases, the period of the satellite ._____

increases

Which of the moon's properties prevents it from being pulled inward by Earth? gravity inertia shape structure

inertia