physics chapter 4 test

A 75-N box rests on a perfectly smooth horizontal surface. The minimum force need to start the box moving is

A 75-N box rests on a perfectly smooth horizontal surface. The minimum force need to start the box moving is

any horizontal force greater than zero

In a collision between a huge SUV and a small hybrid car, the SUV exerts a larger force on the hybrid than the hybrid exerts on the SUV.

false

You are in a train traveling on a horizontal track and notice that a piece of luggage starts to slide directly toward the front of the train. From this observation, you can conclude that this train is

slowing down

If you pound a feather with a hammer, which one feels a greater force

the size of the force is always exactly the same on both of them

A satellite is in orbit around the earth. Which one feels the greater force?

earth and the satellite feel exactly the same force

In order to lift a bucket of concrete, you must pull up harder on the bucket than the bucket pulls down on you

false

If the rockets of a spaceship in outer space (far from all gravity) suddenly lose power and go off, the spaceship will gradually slow to a stop.

false

A bucket is being lowered by a very light rope with a constant downward velocity. The tension in the rope must be

equal to the weight of the bucket

Bill and his daughter Susan are both standing on identical skateboards (with really good frictionless ball bearings), initially at rest. Bill weighs three times as much as Susan. Bill pushes horizontally on Susan's back, causing Susan to start moving away from Bill. Just after Bill stops pushing,

Susan and bill are moving away from each other, and Susans speed is three times that of Bill.

A small car and a large SUV are at a stoplight. The car has a mass equal to half that of the SUV, and the SUV can produce a maximum accelerating force equal to twice that of the car. When the light turns green, both drivers push their accelerators to the floor at the same time. Which vehicle pulls ahead of the other vehicle after a few seconds?

its a tie

An object is moving with constant non-zero velocity. Which of the following statements about it must be true?

the net force on the object is zero

A box is placed on a table which rests on the floor. The box pushes on the table; the reaction force to the box's push on the table is the table's push on the floor.

false

You are standing in a moving bus, facing forward, when you suddenly slide forward as the bus comes to an immediate stop.  What force caused you to slide forward?

there is not a force causing you to slide forward

Suppose a particle is accelerated through space by a 10 N force.  Suddenly the particle encounters a second force of 10 N in the opposite direction from the first force.  The particle with both forces acting on it

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

A hockey puck sliding on a frictionless surface will eventually slow down due to its inertia.

false

which of the following is the cause of an acceleration or a change in an objects motion?

force

How much does a 3.0-kg bag of bolts weigh?

29.4 N

An object weighs 30N on Earth A second object weighs 30N on the moon which has the greater mass

the one on the moon

compared to its weight on Earth, a 10-kg object on the moon will weigh

less

a bag of sports equipment has a mass of 10.0 kg and a weight of

98 N

A woman stands w 2 feet on a scale, the scale reads 280N. When she lifts 1 foot the scale reads

280 N

A person weighing 300N is standing on a bathroom scale in an elevator.  The elevator begins rising with a constant non-zero acceleration.  The bathroom scale read a number

greater than 300 N

Gravitational forces on the moon are approximately one-sixth of the value on Earth. What is the mass and what is the weight on the moon of a 60-kilogram student?

mass=60 kilograms and weight=100 N

Inertia is NOT a force.  A rightward-moving object naturally maintains its state of rightward motion in the absence of forces.  A rightward force is not required to keep such an object moving rightward.

true

An object is at rest. What can be concluded about the forces acting upon the object?

the forces that act upon the object have a strength of 0 Newton

Objects at rest remain at rest and objects in motion remain in motion, unless acted upon by an outside force

newtons 1st law

when a force is exerted on an object the object will exert a force equal in magnitude and opposite in direction

newtons 3rd law

fnet=ma

newtons 2nd law

will cause an object to accelerate

unbalanced forces

create a situation where net force=0N

balanced forces