Concepts
Concepts
Formula
Formula
100

An object that experiences a push or a pull has a(n) ____ exerted on it.



force

100

Moving faster as you pedal your bicycle harder on a level road demonstrates Newton’s ____ law.

second

100

What force is required to accelerate a 10.0 kg bowling ball at 3.0 m/s2 forward?

F = ma = (10.0 kg)(3.0 m/s2 forward) =
30 N forward

100

A rocket weighs 2.0 × 10^7 N. Its engines exert an upward force of 25 × 10^6 N at liftoff.

    What is the mass of the rocket at liftoff?



 m =  =

200

Forces have both direction and ____ .



magnitude

200

According to Newton’s ____ law, an object with no net force acting on it remains at rest or in motion with a constant velocity.

1st

200

What is the mass of a cat that weighs 90.0 N?

m =  = 90.0N/9.8m/s/s=9.18kg

200
  1. A rocket weighs 2.0 × 10^7 N. Its engines exert an upward force of 25 × 10^6 N at liftoff. What is the rocket’s acceleration when it lifts off?



b.    a =  =

        =

        =



300

An object with no net force acting on it is in ____ .



equilibrium

300

    If you push against a wall, the wall pushes back against you with ____ force.

equal

300

How large is the tension in a rope that is supporting a 9.2-kg bucket?

FT = Fg and Fg = mg
Therefore,
FT = mg = (9.2 kg)(9.8 N/kg) = 90.16 N

300
  1. A 47-N box is pulled along a frictionless horizontal surface by a 25-N weight hanging from a cord on a frictionless pulley.

 How large are the box’s acceleration and mass?



m1 =  =

    m2 =  =

    a =  =

400

An object’s weight depends upon the ____ and the object’s mass.



  1. gravitational field

400

An object is in equilibrium if ____ .

the net force on it is zero    

400

A net force of 165 N upward acts on an object. Find the single force that will produce equilibrium.

A force of 165 N downward will produce equilibrium.

400
  1. A 47-N box is pulled along a frictionless horizontal surface by a 25-N weight hanging from a cord on a frictionless pulley.

 How large is the force exerted on the cord?



Fcord = m2a = (2.6 kg)(3.4 m/s2) = 8.8 N



500

According to Newton’s third law, the two forces that make up an interaction pair are equal in ____ but ____ in direction.



magnitude, opposite

500

    The force exerted by any segment of a string or rope on an adjoining segment is ____ .



tension

500

An elevator with a mass of 1.10 × 10^3 kg accelerates upward at 0.45 m/s2. What is the force acting on the elevator’s support cable?



  1. FT = Fnet + Fg 

    = ma + mg = m(a + g)

    = (1.10 × 10^3 kg)(0.45 m/s2 + 9.8 N/kg)

    = 1.1 × 10^4 N



500
  1. A stepping stool is constructed so that it collapses when the normal force exceeds 1100 N. You are assisting a welder who weighs 106 kg and is on the top step of the stepping stool. You pass the welder a torch and a fuel tank that weigh a combined 14 kg. The welder refuses to take both items from you. Explain why. Show your calculations.



  1. Fwelder = mg = (106 kg)(9.8 N/kg) 

    = 1.00 × 103 N

    Ftotal = (mwelder + mequipment)g 

    = (106 kg + 14 kg)(9.8 N/kg) = 1100 N

Adding the torch and fuel tank to the weight of the welder would exceed the 1100 N specified for this stool.



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