practice questions 3

Question 1

according to the graph above, during which intervals the car at rest

Answer 1

5.0s to 10.0s

Question 2

how long will it take a car to accelerate from 20m/s to 26m/s at a rate of 1.4 m/s2

Answer 2

4.3s
V final - V initial over T
= 26-20 divided by 1.4
=4.28 
=4.3

Question 3

which point on this position vs time graph has the fastest speed ?

Answer 3

point 2

Question 4

lisa tosses a flying disc to her friend. the more force she uses to throw the disc the greater the acceleration .which of physics laws of motion explains that the disc has a greater acceleration when it is thrown with greater force?

Answer 4

newtons second law .

Question 5

how would a man on mars weigh if he had a mass of 75 kilograms and the acceleration due to the gravity on the surface of mars is 3.7 m/s 2

Answer 5

277.5 newtons
F=ma
F=75 times 3.7 m/s2
=277.5

Question 6

the acceleration of gravity on the surface of earth is 9.8 m/s/s.on the moon the acceleration of a gravity is 1/6 of this value. if a woman has a mass of 6o kg , what will her weight be on the moon in newtons.

Answer 6

98 n
F=ma
Force=6 divided by 1/6 = 10 times 9.8= 98

Question 7

a book rests on a table .the force of gravity pulls down on the book with a force of 20 newtons .what prevents the books from accelerating downward at 9.8 m/s2 ?

Answer 7

the table presses back up on the book with an equal and opposite force at 20 newtons.

Question 8

an object on earth has a mass of 150.00 kilograms (KG) and a weight of 1,470.00 newtons (N) .which statement correctly describes the mass and the weight of this object on mars ?

Answer 8

the mass of the object on mars would be 150.00 kg and the weight would be 556.50N .

Question 9

a 100n object and a 50 n object are placed on scles and b respectively inside an elevator ascending with constant velocity3.0 m/s . which statement below correctly describes the readings on the scales inside the elevator ?

Answer 9

scale a reads exactly 100-n ,and scale b reads exactly 50-n

Question 10

kyle is playing volleyball , it reaches it maximum height and then falls toward the ground due to the force of gravity .which statement best describes the interaction between the ball and earth?

Answer 10

the ball and earth attract eachother with equal magnitudes of gravitational force .

Question 11

the diagram depicts earth, the moon, and the attractive fundamental force between them.which of the following fundamental forces is represented by the diagram.

Answer 11

gravitational

Question 12

which list corretly ranks the four fundamental forces of nature from strongest to weakest?

Answer 12

strong nuclear,electromagnetic, weak nuclear,and gravitational.( sewg)56

Question 13

between any two objects with mass, which of the following fundamental forces acts between the two objects only as an attractive force?

Answer 13

gravitational force.

Question 14

in physics class, jon stands on a ladder and a feather while keisha makes a video recording of the experiment . the mass of the hammer is 0.454 kg and the mass of the feather is 2.g using the video reording , jon and keisha calculate the accelerations of each object at a different time ,as shown in the table.

Answer 14

the feathers greater air resistance decreases its acceleration.

Question 15

newtons second law of motion stales that : f-ma where f is the force an object of mass m , which is accelerating at a rate of at archery practice vladimir tests a bow and arrow he has recently designed .he is able to accelerate 24.0 arrow at an average rate of 70.0 m/s 2. what is the bows average force on the arrow.

Answer 15

1.68 n

F=ma
Force= 24 times 70 =1,680 divided by 1000=1.68

Question 16

which objects are being subjected to a net force ?

Answer 16

satellite,boat,ball.

Question 17

the law of universal gravitation can be expressed as f=gm1-m2/r2 where f is the force of attraction , g is the uni-r2 versal graitational constant ( 6.674 x 10-11N.M.2Kg-)m1 is the mass of the second object , and r is the distance between the centers if the 2 objects.A 1,2 -kilogram container of sugar sits 2.3 meters away from a 9.4 - kilogram bag of flour,what is the gravitational force of attraction between the sugar and the flour.

Answer 17

1.4x-10-10n

Question 18

which statement best explains the energy transfer as the boy moves from position 2 to position 3

Answer 18

the boys kinetic energy is transferred to the boy’s potential energy .

Question 19

an astronaut drops a 1.0 kg object and a 5.0kg object on the moon .both objects fall a total distance of 1.0m

Answer 19

they have each gained one half of their maximum kinetic energy.

Question 20

which of the following increases when a medal spring is stretched horizontally

Answer 20

potential.

Question 21

the figure below shows a wagon that moves from point x to point y.which of the following best describes the wagons change in energy as it coasts from point x to point y

Answer 21

the wagon has more gravitational potential energy at point y than at point x

Question 22

which of the folllowing describes the mechanical energy of a cart at rest at the top of a steep hill.

Answer 22

the cart’s mechanical energy is potential.

Question 23

the diagrams below show a man swinging a golf club . the kinetic energy at the golf club at point y is more than the potential energy of the club at point x . which of the following statements best explains why this fact does not violate the law of conversation of energy.

Answer 23

energy is added by the man to the golf club from point x to point y .

Question 24

a cardboard box has four forces acting upon it , as shown the diagram below . what is the magnitude of the unknown force, f unknown , acting on the box if the box is accelerating at 2.0 m/s2 to the right.

Answer 24

6

Question 25

A car is traveling at a constant speed of 12m/s , when the driver accelerates the car reaches a speed of 26 m/s in 6s what is the acceleration of the car

Answer 25

2.3 s

V final - V initial over time
=26-12 divide by 6
=2.3ms2

Question 26

a cart at the top of the hill is released and rolls down the hill which of the following describes the energy of the cart just as it reaches the bottom of the hill.

Answer 26

the cart has maximum kinetic energy.