Physics-Kelly (No diagram questions)

203. A book weighs 4 N. When held at rest in your hands, the net force on the book is

0 N

228. A 6-N falling object encounters 6 N of air resistance. The magnitude of the net force on the object is

0 N

128. A ball is thrown straight up. At the top of its path its instantaneous speed is

0 m/s

199. When an object reaches terminal velocity its acceleration is

0 m/s squared

141. What is the maximum resultant possible when adding a 2-N force to an 8-N force?

10 N

37) Fr. LaSalle leaves a 10 N Bible open on the altar at mass. What is the normal force on the Bible?

10 N

129. A ball is thrown straight up. At the top of its path its acceleration is

10 m/s squared

67. The acceleration of gravity on Earth is approximately which of the following

10 m/s squared

200. A 10-kg brick and a 1-kg book are dropped in a vacuum. The force of gravity on the 10-kg brick is

10 times as much as the force on the 1-kg book.

192. The mass of a lamb that weighs 110 N is about

11 kg

49) A model rocket weighs 125 N. Its engine exerts an upward thrust of 200 N at lift-off. What is the approximate mass of the rocket?

12.5 kg

19) A car carrying a 8 kg test dummy crashes into a wall at 15 m/s and is brought to rest in 0.1 s. Find the magnitude of average force exerted by the seat belt on the dummy

1200 N

208. A box is dragged without acceleration in a straight-line path across a level surface by a force of 13 N. What is the frictional force between the box and the surface?

13 N

47) How much force is required to keep a 650 N box moving at constant velocity across the floor if the friction force between the box and floor is 150 N

150 N

75. What is the resulting speed of an airplane with an airspeed of 120 m/s north with it encounters a cross with of 90 m/s west?

150 m/s

223. A 20-N falling object encounters 4 N of air resistance. The magnitude of the net force on the object is

16 N

45) If you push horizontally on a crate with a force of 160 N, it slides across the floor at constant velocity. How much friction force must be acting on the crate?

160 N

204. A girl pulls on a 10-kg wagon with a constant force of 20 N. What is the wagon's acceleration?

2 m/s squared

170. A piece of putty moving with 2 units of momentum strikes and sticks to a heavy bowling ball that is initially at rest. After the putty sticks to the ball, both are set in motion with a combined momentum that is

2 units

132. If a ball were equipped with a speedometer and allowed to fall freely on a planet where the acceleration due to gravity is 23 m/s squared, the reading on the speedometer would increase each second by

23 m/s

202. Suppose the force of friction on a sliding object is 25 N. The force needed to maintain a constant velocity is

25 N

145. A girl whose weight is 500 N hangs from the middle of a bar supported by two vertical strands of rope. What is the tension in each strand?

250 N

217. If you pull horizontally on a desk with a force of 150 N and the desk doesn't move, the friction force must be 150 N. Now if you pull with 250 N so the desk slides at constant velocity, the friction force is

250 N

36) Max decides to demonstrate how strong he is by pulling two horses going in opposite directions. If the each horse can only pull with 250 N, what the tension in the ropes?

250 N

39) A girl whose weight is 500 N hangs from the middle of a bar supported by two vertical strands of rope. What is the tension in each strand?

250 N

201. When a woman stands with two feet on a scale, the scale reads 280 N. When she lifts one foot, the scale reads

280 N

139. Suppose a stone weighs 8 N in the air, but in water it weighs only 5 N. What is the buoyant force acting on the stone?

3 N

177. A ball is moving at 6.0 m/s and has a momentum of 24.0 kg·m/s. What is the ball's mass

4 kg

225. You pull horizontally on a 50-kg crate with a force of 450 N and the friction force on the crate is 250 N. The acceleration of the crate is

4 m/s squared

112. How much work is done on a 20-N crate that you lift 2 m?

40 J

238. Two people pull on a rope in a tug-of-war. Each pulls with 400 N of force. What is the tension in the rope?

400 N

232. A person is attracted towards the center of Earth by a 440-N gravitational force. The force with which Earth is attracted toward the person is

440 N

176. A 4.0-kg ball has a momentum of 20.0 kg·m/s. What is the ball's speed?

5 m/s

248. What is the resultant of a 3-unit vector and 4-unit vector at right angles to each other?

5 units

227. A jumbo jet cruises at a constant velocity when the total thrust of the engines on the jet is 50,000 N. How much air resistance acts on the jet?

50,000 N

178. A 5.0-kg chunk of putty moving at 10.0 m/s collides with and sticks to a 7.0-kg bowling ball that is initially at rest. The bowling ball with its putty passenger will then be set in motion with a momentum of

50.0 kg·m/s

40) Vanessa weighs 500 N and hangs from one vertical strand of rope. If the spring scales do not add any weight, what is the reading on each spring scale?

500 N

237. A woman weighing 550 N sits on the floor. She exerts a force on the floor of

550 N

175. A 2-kg ball is thrown at 3 m/s. What is the ball's momentum?

6 kg·m/s

123. A car starts from rest and after 7 seconds it is moving at 42 m/s. What is the car's average acceleration?

6 m/s squared

48). Two children having a disagreement pull a on a sled in opposite directions. One pulls with a force of 200 N east, the other with a force of 125 N west. A friction force of 10 N exist between the sled and the surface. Determine the net force on the sled.

65 N

224. A sportcar has a mass of 1500 kg and accelerates at 5 meters per second squared. What is the magnitude of the force acting on the sportscar?

7,500 N

95. An arrow in a bow has 70 J of potential energy. Assuming no loss of energy to heat, how much kinetic energy will it have after it has been shot?

70 J

110. How many joules of work are done on a box when a force of 25 N pushes it 3 m?

75 J

226. How much force is needed to accelerate a 4.0-kg physics book to an acceleration of 2.0 m/s squared?

8 N

247. Which best approximates the resultant of a pair of 6-unit vectors at right angles to each other?

8 units

195. A bag of sports equipment has a mass of 10.0 kilograms and a weight of

98 N.

96. Energy is changed from one form to another with no net loss or gain

Always true

71) What represents Force

F

38) Fr. LaSalle leaves a 10 N Bible open on the altar at mass. What is the pressure on the Bible?

I depends on if the Bible is opened or closed

58) Air resistance plays a huge role during skydiving. During a skydive what happens to the acceleration of the skydiver before terminal velocity is reached or a parachute is opened?

It increases

44) You are helping your aunt move a piano on wheels from one room to another. When you push the piano horizontally, it moves at constant speed. What can you say about the piano?

It is in dynamic equilibrium

69) Which is the unit of Energy?

Joule

89) The unit of work is the

Joule

23) For the same force, is the change in momentum of a cannon ball greater when shot from a long-barrel cannon or a short-barrel cannon?

Long barrel

118. One possible unit of speed is

Miles per hour light years per century kilometers per hour.

134. If you drop a feather and a coin at the same time in a vacuum tube, which will reach the bottom of the tube first?

Neither-they will both reach the bottom at the same time.

245. At the instant a ball is thrown horizontally with a large force, an identical ball is dropped from the same height. Which ball hits the ground first?

Neither. They both hit the ground at the same time.

193. Which has more mass, a kilogram of feathers or a kilogram of iron?

Neither—they both have the same mass.

151. Which has more momentum, a large truck moving at 30 miles per hour or a small truck moving at 30 miles per hour?

The large truck

70) What represents final speed?

Vf

117. Speed is

a measure of how fast something is moving always measured in terms of a unit of distance divided by a unit of time. the distance covered per unit time.

144. Equilibrium occurs when

a. all the forces acting on an object are balanced. b. the sum of the +x forces on an object equals the sum of the -x forces. c. the net force on the object is zero. d. the sum of the upward forces equals the sum of the downward forces.

188. Friction

a. comes from microscopic bumps that act as obstructions to the object's motion. b. is the name given to the force acting between surfaces sliding past one another. c. acts in a direction that opposes the motion of an object.

242. In order to find the components of a vector, you should

a. draw the vector with correct magnitude and orientation. b. measure the sides of the rectangle. c. draw a rectangle so that the vector is the diagonal

149. In order to find the components of a vector, you should

a. draw the vector with correct magnitude and orientation. b. measure the sides of the rectangle. c. draw a rectangle so that the vector is the diagonal.

155. In order to increase the final momentum of a golf ball, we could

a. increase the force acting on it. b. follow through when hitting the ball. c. increase the time of contact with the ball. d. swing as hard as possible.

198. The acceleration produced by a net force on an object is

a. inversely proportional to the mass of the object. b. directly proportional to the magnitude of the net force. c. in the same direction as the net force.

153. If the momentum of an object changes and its mass remains constant,

a. it is accelerating (or decelerating). b. there is a force acting on it. c. its velocity is changing.

165. A car traveling along the highway needs a certain amount of force exerted on it to stop. More stopping force may be required when the car has

a. less stopping distance. b. more momentum. c. more mass.

241. When representing velocity as a vector

a. the direction of the arrow shows the direction of motion. b. the length of the arrow represents the speed. c. the length of the arrow is drawn to a suitable scale.

166. The force of an apple hitting the ground depends upon

a. the speed of the apple just before it hits. b. the time of impact with the ground. c. whether or not the apple bounces. d. air resistance on the apple as it falls.

181. The law of inertia states that an object

a. will continue moving at the same velocity unless an outside force acts on it. b. will continue moving in a straight line unless an outside force acts on it. c. that is not moving will never move unless a force acts on it. d. at rest will remain at rest unless acted on by an outside force.

130. When something falls to the ground, it accelerates. This acceleration is called the acceleration due to gravity and is symbolized by the letter g. What is the value of g on Earth's surface?

about 10 m/s squared

167. When you jump off a step, you usually bend your knees as you reach the ground. By doing this, the time of the impact is about 10 times more what it would be in a stiff-legged landing, and the average force on your body is reduced by

about ten

124. In the absence of air resistance, objects fall at constant

acceleration

205. An object has a constant mass. A constant force on the object produces constant

acceleration

68) Which of the following variables is measured in m/s squared

acceleration

147. What is needed to describe a vector quantity?

both magnitude and direction

182. The law of inertia applies to

both moving and nonmoving objects

163. A cannon recoils from launching a cannonball. The speed of the cannon's recoil is small because the

cannon has far more mass than the cannonball

109. A pulley system can

change the direction of the force and multiply the force

209. Suppose a particle is accelerated through space by a constant 10-N force. Suddenly the particle encounters a second force of 10-N in a direction opposite to that of the first force. The particle

continues at the speed it had when it encountered the second force

222. You are on a frozen pond, and the ice starts to crack. If you lie down on the ice and begin to crawl, this will

decrease the pressure on the ice

99. Rockets are launched from an airplane in the forward direction of motion. The kinetic energy of the airplane will be

decreased

218. When the angle of an incline with a block resting on it increases, the normal support force

decreases

162. A freight train rolls along a track with considerable momentum. If it were to roll at the same speed but had twice as much mass, its momentum would be

doubled

220. If the force acting on a cart doubles, what happens to the cart's acceleration?

doubles

210. Pressure is defined as

force per area.

84. In physics, work is defined as

force times distance

196. Accelerations are produced by

forces

236. According to Newton's third law, if you push gently on something, it will push

gently on you

187. An object following a straight-line path at constant speed

has zero acceleration

174. While roller-skating, Granny collides with her tiny grandson Ambrose who is at rest. Ignoring any friction effects, Ambrose's speed after the collision will be greatest when

he and Granny make a bouncing collision, each going in opposite directions

92. Gravitational potential energy is the energy an object has because of its

height.

173. A cannonball shot from a long-barrel cannon travels faster than one shot from a short-barrel cannon because the cannonball receives a greater

impulse

154. The momentum change of an object is equal to the

impulse acting on it

156. The reason padded dashboards are used in cars is that they

increase the time of impact in a collision

219. A block is at rest on an incline. The force of friction necessary to prevent the block from sliding increases when the incline angle is

increased

189. One object has twice as much mass as another object. The first object also has twice as much

inertia

119. When you look at the speedometer in a moving car, you can see the car's

instantaneous speed.

197. How does acceleration of an object change in relation to its mass? It is

inversely proportional.

221. Suppose a cart is being moved by a force. If suddenly a load is dumped into the cart so that the cart's mass doubles, what happens to the cart's acceleration?

it halves

234. An unfortunate bug splatters against the windshield of a moving car. Compared to the deceleration of the car, the deceleration of the bug is

larger

190. Compared to its weight on Earth, a 10-kg object on the moon will weigh

less

240. A scalar is a quantity that has

magnitude

239. A vector is a quantity that has

magnitude and direction

65) Which of the following is measured in kg?

mass

150. The momentum of an object is defined as the object's

mass times its velocity

246. An airplane flying into a head wind loses ground speed, and an airplane flying with the wind gains ground speed. If an airplane flies at right angles to the wind, then ground speed is

more

172. A table tennis ball moving forward with 5 units of momentum strikes and bounces backward off a heavy bowling ball that is initially at rest and free to move. The bowling ball is set in motion with a momentum of

more than 5 units.

184. If the force of gravity suddenly stopped acting on the planets, they would

move in straight lines tangent to their orbits.

211. The unit of pressure is

newtons per square meter (or pascals).

230. A high school student hits a nail with a hammer. During the collision, there is a force

on the nail and also on the hammer

229. If shopping cart A has five times more mass in it than shopping cart B and the two carts are pushed with equal forces, you can expect the acceleration of shopping cart A to be

one fifth times that of shopping cart B.

169. A moving freight car runs into an identical car at rest on the track. The cars couple together. Compared to the velocity of the first car before the collision, the velocity of the combined cars after the collision is

one half as large.

148. A scalar quantity has

only magnitude

180. Friction is a force that always acts

opposite to an objects motion

100. A job is done slowly, and an identical job is done quickly. Both jobs require the same amount of work but different amounts of

power

137. If an object has a density greater than the density of water, it will _____.

sink

235. A large truck and a small car traveling at the same speed have a head-on collision. The vehicle to undergo the greater change in velocity will be

small car

179. A meteor that originally was heading south breaks up into two chunks. One of the chunks moves southwest. The second chunk was not immediately found, but scientists guessed that they should look for an object heading

southeast

146. The weight of a person can be represented by a vector that acts

straight down, even if the person is standing on a hill

171. The force that accelerates a rocket into outer space is exerted on the rocket by

the exhaust gas

185. A sheet of paper can be withdrawn from under a container of milk without toppling it if the paper is jerked quickly. The reason this can be done is that

the milk carton has inertia.

157. A table tennis ball launcher is fired. Compared to the force on the ball, the force on the launcher is

the same

158. A table tennis ball launcher is fired. Compared to the impulse on the ball, the impulse on the launcher is

the same

191. Compared to its mass on Earth, the mass of a 10-kg object on the moon is

the same

206. A force of 3 N accelerates a mass of 3 kg at the rate of 1 m/s squared. The acceleration of a mass of 6 kg acted upon by a force of 6 N is

the same

216. Aunt Minnie throws a rock downward, and air resistance is negligible. Compared to a rock that is dropped, the acceleration of the rock after it is thrown is

the same

233. An unfortunate bug splatters against the windshield of a moving car. Compared to the force of the car on the bug, the force of the bug on the car is

the same

125. A ball is thrown upwards and caught when it comes back down. In the absence of air resistance, the speed of the ball when caught would be

the same when first thrown

213. A tennis ball and a solid steel ball with the same diameter are dropped at the same time. Which ball has the greater force acting on it?

the steel ball

164. In order to catch a ball, a baseball player moves his or her hand backward in the direction of the ball's motion. Doing this reduces the force of impact on the player's hand principally because

the time of impact is increased.

244. The horizontal component of a projectile's velocity is independent of

the vertical component of its velocity

93. The amount of potential energy possessed by an elevated object is equal to

the work done in lifting it

159. Momentum of a system is conserved only when

there is no net external force acting on the system.

214. A tennis ball and a solid steel ball with the same diameter are dropped at the same time. In the absence of air resistance, which ball has the greater acceleration?

they would be the same

152. Compared to a sports car moving at 30 miles per hour, the same sports car moving at 60 miles per hour has

twice as much momentum.

207. A push on a 1-kilogram brick accelerates the brick. Neglecting friction, to equally accelerate a 10-kilogram brick, one would have to push

with 10 times as much force

168. Recoil is noticeable if you throw a heavy ball while standing on roller skates. If instead you go through the motions of throwing the ball but hold onto it, your net recoil velocity will be

zero

186. The force required to maintain an object at a constant speed in free space is equal to

zero

183. After a cannonball is fired into frictionless space, the amount of force needed to keep it going equals

zero, since no force is necessary to keep it moving

143. What is the minimum resultant possible when adding a 5-N force to an 8-N force?

3 N

21)What is the magnitude of the impulse on an 0.52 kg egg falling at 6 m/s when it stops in 0.8 s?

3.12 kg*m/s

140. A 15-N force and a 45-N force act on an object in opposite directions. What is the net force on the object?

30 N

86. In the absence of friction, Luke lifts a 600 N block up 3 m. Mitch decides to push the same block up a 6 m ramp. If Luke used 600 N of force, how much force did Mitch use?

300 N

142. A 5-N force and a 30-N force act in the same direction on an object. What is the net force on the object?

35 N

50) A textbook sitting on a table weighs 250 N. If you push straight down on the book with a force of 125 N, what is the normal force acting on the book?

375 N

34) Nic and Jalen decide have a tug of war to see who is the strongest guy in their group. If Nic is winning and his spring scale reads 500 N, what is the reading on Jalen's spring scale?

500 N

135. If a projectile is fired straight up at a speed of 30 m/s, the total time to return to its starting point is about

6 seconds

104. Which has greater kinetic energy, a car traveling at 30 km/h or a half-as-massive car traveling at 60 km/h?

60 km/h

127. Suppose you take a trip that covers 180 km and takes 3 hours to make. Your average speed is

60 km/h

133. A freely falling object starts from rest. After falling for 6 seconds, it will have a speed of about

60 m/s

111. How much power is required to do 40 J of work on an object in 5 seconds?

8 Watts

Space Cadet Logan and Space Cadet Kai are speeding away from our solar system in the space shuttle. On their journey to a distance star the rocket engines cut out. Immediately after the rocket engines cut out will the space shuttle...

. continue on at the speed it was going when the engines cut out.

116. Sue can easily lift a 45.0-N rock with the help of a lever. When she pushes down with 20.0 N of force, she lifts the rock 0.3 meters. How far does she move her arms to do this?

.7 m

55) What is the net force acting on a car moving at a constant velocity of 55 km/h?

0

59) Air resistance plays a huge role during skydiving. When a sky diver is at terminal velocity what is his/her acceleration?

0 m/s squared

114. It takes 80 J to push a large box 8 m across a floor. Assuming the push is in the same direction as the move, what is the magnitude of the force on the box?

10 N

131. A car accelerates at 2 m/s squared. Assuming the car starts from rest, how much time does it need to accelerate to a speed of 20 m/s?

10 seconds

113. Suppose a moving car has 3000 J of kinetic energy. If the car's speed doubles, how much kinetic energy will it then have?

12,000 J

22) In order prevent his egg from breaking Gabe built a device that was very good at crumpling. If the device and the egg have a mass of 0.64 kg and hit the ground at a speed of 6 m/s what is the magnitude of the force the egg experienced if it stopped in 0.3 s?

12.8

79. An airplane is flying forwards at 144 km/h and encounters a crosswind of 60 km/h as shown below. What is the resultant speed of the airplane?

156 km/h

53) A green wagon is pulled along the sidewalk by a force of 30 N, with a 12 N frictio force opposing the motion. The force of gravity on the wagon is 35 N. What is the net force acting on the wagon?

18 N

20)A 8-kg fish swimming 5 m/s swallows an absentminded 2-kg fish swimming toward it at a speed that brings both fish to a halt immediately after lunch. Find the speed of the approaching smaller fish before lunch

20 m/s

51) A model rocket weighs 100 N. Its engine exerts an upward thrust of 300 N at lift-off. What is the acceleration at lift-off?

20 m/s squared

57) When a cannnon fires, the exploding gunpowder creates a force that sends the cannon ball forward and sends the cannon backwards. The acceleration of the cannon ball is ____________________ the acceleration of the cannon.

Greater than

32)Will is being chased by a 4,000 kg angry elephant at full speed. Up ahead he sees 3 escape paths: I. A straight ahead path with no bends. II. A path that slightly bends to the left. III. A path that makes a sharp 90o bend to the left. Using your knowledge of Newton's 1st law, determine which path would be the best choice for Will to escape using the elephant's own mass against it.

III

85) In the absence of friction, Ogagaogene lifts a 200 N block of ice up 1 m. While Marlene slides an identical block up a 5 m ramp. How much work did Marlene do compared to Ogagaogene?

The same amount

56) When a cannnon fires, the exploding gunpowder creates a force that sends the cannon ball forward and sends the cannon backwards. The force on the cannon ball is ____________________ the force on the cannon.

The same as

87. If you lift one load up two stories, how much work do you do compared to lifting one load up only one story?

Twice as much

91. The unit of power is the

Watt

101. Which requires more work: lifting a 70-kg sack vertically 2 meters or lifting a 35-kg sack vertically 4 meters?

both require the same amount of work

126. A ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting point. During this time the acceleration of the ball is always

directed downward

88. If Nellie Newton pushes an object with twice the force for twice the distance, she does

four times the work

138. When you float in salt water compared to floating in fresh water, the buoyant force that supports you is _____.

greater

29)If Dan drops a pencil in a bus that starts slowing down while the pencil is in the air, the pencil will land

in front of Dan

30) Thomas the teddy bear sits at rest in the middle of a wagon. If Jack the jokester comes along and quickly pulls the wagon forward, where will Thomas the teddy bear end up?

in the back of the wagon

98. When a car's speed triples, its kinetic energy

increases by nine times

108. The ratio of output force to input force of a simple machine is called the

mechanical advantage

103. An object that has kinetic energy must have

momentum

106. If the velocity of a moving object doubles, then what else doubles?

momentum

66. Which of the following measurements has units of kg x m/s

momentum

102. An object that has kinetic energy must be

moving

115. If Kelly the skater's speed increases so he has three times the momentum, then his kinetic energy increases by

nine times

35) Max decides to demonstrate how strong he is by pulling two horses going in opposite directions. If the each horse can only pull with 250 N, what is the net force on Max?

o

76. Chris can paddle a canoe in still water at 8km/h. If he tries to paddle upstream, in the opposite direction of a river flowing at 8km/h, what is Chris' effective speed to relative to Corey standing on the shore?

o km/h

122. A train travels 6 meters in the first second of travel, 6 meters again during the second second of travel, and 6 meters again during the third second. Its acceleration is

o m/s squared

94. Kinetic energy of an object is equal to

one half the product of its mass times its speed squared

120. Acceleration is defined as the CHANGE in

velocity divided by the time interval.

72) What is measured in the same measurement as Force

weight

82) What is measured in N

weight and force

136. Archimedes' principle says that an object is buoyed up by a force that is equal to the _____.

weight displaced by water

90. Power is defined as the

work done on an object divided by the time taken to do the work.

107. All simple machines that give you a mechanical advantage ideally work on the principle that

work input equals work output