IB Physics

A mass on the end of a string is rotating on a frictionless table in circular motion of radius R1 and undergoes an angular displacement of θ in time t. The string tension is kept constant, but the angular displacement of the mass is increased to 2θ in time t. The radius of the motion changes to R2.

What is R2?

• A. R1/4

• B.  2R1

• C.  4R1

• D. R1 * R2

The angle θ between a ramp and a horizontal surface slowly increases from zero. An object on the ramp does not slide as θ increases. The frictional force on the object is

• constant.

• negligible.

• proportional to cos θ.

• proportional to sin θ.

Tags

NGSS.HS-PS2-1

An object of mass M is accelerated vertically upwards by a motor at a constant acceleration.
The object is initially at rest and reaches a vertical speed of 4.0 m s−1 in 2.0 s. What is the average power output of the motor?

• 8M

• 24M

• 32M

• 48M

Tags

NGSS.HS-PS2-1

A car has an initial speed of 16 m s−1. It decelerates at 4.0 m s−2 until it stops.

What is the distance travelled by the car?

• A.  4 m

  
  

• B.  16 m

  
  

• C.  32 m

  
  

• D.  64 m

  
  

Tags

NGSS.HS-PS2-1

A car travels clockwise around a circular track of radius R. What is the magnitude of displacement from X to Y?

• A.  R(3*pi/2)

• B.  R(pi/2)

• C. R*squareroot(2)

• D. R

An object is travelling with velocity 5 m s−1. The object then accelerates to 15 m s−1 in the same direction.

What is the variation with time of the acceleration of the object?

• 
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• 
• 

Tags

NGSS.HS-PS2-1

A toy balloon floats at the end of a string. A wind blows horizontally to the right. The balloon is in translational equilibrium. What is the free-body diagram of the forces acting on the balloon?

• 
• 
• 
• 

Tags

NGSS.HS-PS2-1

The input power of an electric motor is 200 W. It is used to raise a mass of 10 kg at constant speed.
If the efficiency of the motor is 40 %, through what height will the mass be raised in 1 second?

• A.  0.5 m

• B.  0.8 m

• C.  1.2 m

• D.  2.0 m

Tags

NGSS.HS-PS3-1

What is the definition of an electric field?

• An electric field is a vector field that associates to each point in space the force per unit charge experienced by a test charge at that point.

• An electric field is a measure of the resistance of a material to the flow of electric current.

• An electric field is a scalar quantity that represents the charge density at a point in space.

• An electric field is a type of magnetic field that arises from moving charges.

Tags

NGSS.HS-PS3-5

Explain the concept of magnetic field lines.

• Magnetic field lines are imaginary lines used to represent the direction and strength of a magnetic field.

• Magnetic field lines are static and do not change over time.

• Magnetic field lines are only visible under a microscope.

• Magnetic field lines are physical ropes that emit magnetic energy.

Tags

NGSS.HS-PS3-5