2.1 forces causing centripetal acceleration单词卡 | Quizlet

according to Newton's second law, an object that is accelerating must have a ----- acting on it.

net force

according to Newton's second law, an object that is ------ must have a net force acting on it.

accelerating

an object moving in a circle, such as a ball on the end of a string, must therefore have a ------ applied to it to keep it moving in the ------.

this force is known as the centripetal force.

force, circle

an object moving in a ------, such as a ball on the ------ of a string, must therefore have a force applied to it to keep it moving in the circle.

this force is known as the ------ force.

circle, end, centripetal

in uniform motion ( speed v = ------)

constant

in ------ motion ( speed v = constant )

uniform

in uniform motion, the acceleration is ------- acceleration which is directed towards the centre of the circle at any moment.

centripetal

in ------ motion, the acceleration is centripetal acceleration which is directed towards the ----- of the circle at any moment.

uniform, centre

according to Newton's second law, an object in a circular motion requires a ------directed toward the centre of the circle.

net force

according to Newton's second law, an object in a ------ motion requires a net force directed toward the centre of the circle.

this net force is called -------.

circular, centripetal force

in the absence of centripetal force, the object would not move along a circle but move in a ------, according to Newton's first law.

straight line

in the absence of ------ force, the object would not move along a circle but move in a straight line, according to Newton's first law.

centripetal

when whirling a body attached to a string, a ------ is originated.

tension force

when whirling a body attached to a string, a tension force is originated.

if this tension force is ----- to the direction of motion of a body moving at

------- speed, this force cause the body to move in a ----- path.

thus, tension force behaves as a ---- force.

normal, constant, circular, centripetal

An attractive force exists between the sun and the earth in a direction -----to the path of the earth. This force causes the earth to move in a ---- path around the sun.

in this case, the gravitational force provides as a centripetal force.

perpendicular, circular

An ----- exists between the sun and the earth in a direction perpendicular to the path of the earth. This force causes the earth to move in a path around the sun.

in this case, the -------- provides as a centripetal force.

attractive force, gravitational force

the electric force is also called ------.

Coulomb attractive force

the ------ force between the nucleus and the electron acts as the required ------ force for the electron to move around the nucleus.

Coulomb attractive, centripetal

when a car turns in a circular path or a curve, a ------ exists between the road and the car tires. This frictional force acts ------ to the direction of motion of the car, causing the car to move in a curved path.

frictional force, normally

when a car moves in a circular path which is ---- to the horizontal, the reaction force of the road acts ---- to the car. Resolving this reaction force ( normal force ) into two components, the ----- component acts towards the centre of the circle and helps the car to move in a curved path. The ------ component of -----force is requires centripetal force.

inclined, normally, horizontal, horizontal, normal

when a car moves in a ----- path which is inclined to the ------, the reaction force of the road acts ---- to the car. Resolving this reaction force ( normal force ) into ---- components, the horizontal component acts towards the ----- of the circle and helps the car to move in a ------ path. The horizontal component of -----force is requires centripetal force.

circular, horizontal, normally, two, centre, curved, normal

the upward thrust is also called -----.

lifting force

the upward thrust ( lifting force ) acts ----- to an airplane body. When the airplane tilts, the ----- component acts ------ to the motion of the airplane, causing the aeroplane to turn in a curve. This means that the ----- component of the ---- force on the aeroplane provides the centripetal force.

normally, horizontal, normally, horizontal, lifting

if the frictional force is not ----, such as under wet and slippery conditions, the car will ----- of the ----- path.

sufficient, skid out, circular

if the ----- force is not sufficient, such as under wet and slippery conditions, the car will ----- of the circular path.

frictional, skid out

the car will skid out of the circular path.

to prevent this, the road must be ---- to provide the necessary ----- force to the automobiles so that they take a ----- turn without ------.

banked, centripetal, safe, skidding

the normal force exerted by a ----- road is ---- to the road.

banked, perpendicular

horizontal components of normal force provides the required ----- force.

centripetal

------- of normal force provides the required centripetal force.

horizontal component

for every banked curve, there is a ----- speed at which the entire centripetal force is supplied by the ----- of the normal force, so that ----- between the tires and the road is ---- required.

limiting, horizontal component, frictional force, not

for every------, there is a limiting speed at which the entire centripetal force is supplied by the ----- of the normal force, so that frictional force between the tires and the road is not required.

banked curve, horizontal component

the horizontal component of the normal force towards the centre of the curve of radius r just----- the centripetal force.

equals

the horizontal component of the normal force towards the centre of the curve of radius r just equals the ------ force.

centripetal

the gravitational force of the sun acting on the Earth causes the earth to move in a circular path

True

The centrifugal force is needed for an object to move in a circle

False

The direction of the centripetal acceleration is tangential to the circular path

False

For the banked curved road, the frictional force is not essential

True

For every banked curve, the frictional force between the tires and the road is not important

True

The greater the mass of the car, the smaller the limiting speed for a certain banking angle.

False

When we swing a ball on the end of a string in a circle, the ——- in the string provides the required centripetal force.

tension

The centripetal force is ——- to the direction of the motion of the body in circular motion.

normal

When a car turns around a level curved path, the ——- force provides the required centripetal force.

frictional

When a car turns around a level curved path, the frictional force behaves as a ———force

centripetal

On an unbanked road, the —— force is supplied by friction between the tires and the road.

centripetal

The curved road must be banked to provide the necessary——- force to the automobiles.

centripetal