2023, Prova 2

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1. 

   QUESTION 1 (3 marks) Describe the effects of relativistic travel on an object.

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2. 

   QUESTION 2 (5 marks) In a frictionless system, object A rests on an inclined plane and object B undergoes horizontal circular motion. The two objects are connected by a length of string as shown. 7.0 kg 3.0 kg Not to scale 30° A B Glass tube Pulley 26 cm Determine the speed of object B needed for object A to remain stationary. Show your working. Speed = m s-1 (to two significant figures)

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3. 

   QUESTION 3 (8 marks) Three charges are in a straight line as shown. r 2r S +5.0 µC Net force on T = +2.8 N +5.0 µC +40 µC T U a) Calculate the electric field strength at T. Show your working. [2 marks] Electric field strength = N C-1 (to two significant figures) b) Determine the value of r. Show your working. [6 marks] r = m (to two significant figures)

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4. 

   QUESTION 4 (3 marks) Two objects on different planets experience different accelerations due to gravity. Object Mass (kg) Acceleration due to gravity (m s-2) A 79 1.6 B 32 3.7 Determine which object has the greatest force acting on it. Show your working.

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5. 

   QUESTION 5 (4 marks) Describe what happens when light is shone onto a metallic surface in the context of the photoelectric effect.

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6. 

   QUESTION 6 (10 marks) A ball is thrown with an initial velocity of 8.0 m s-1 into a bucket as shown. 1.8 m 3.0 m Not to scale 50° a) Calculate the time taken for the ball to reach its maximum height. Show your working. [4 marks] Time = s (to two significant figures) b) Calculate the magnitude of the ball’s final velocity when it enters the bucket. Show your working. [6 marks] Final velocity = m s-1 (to two significant figures)

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7. 

   QUESTION 7 (5 marks) Discuss the nature of light by describing evidence from two key experiments.

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8. 

   QUESTION 8 (6 marks) A length of wire, AB, is placed across an incomplete loop sitting within a magnetic field as shown. Wire AB then moves with a constant velocity of 40 m s-1, creating an induced EMF of 23 µV. 1.4 m Not to scale A B Direction of movement a) Determine the magnitude of the magnetic field strength experienced by the loop. Show your working. [4 marks] Magnetic field strength = T (to two significant figures) b) Draw a conclusion about the direction of the induced current within the loop. Justify your reasoning.  [2 marks]

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