IB Physics: Three Exam Questions with Solutions

Introduction to IB Physics

The International Baccalaureate (IB) Physics curriculum challenges students with concepts that blend theoretical understanding and practical application. Success in this subject often hinges on students' ability to tackle exam questions effectively. In this article, we present ten carefully selected IB physics exam questions along with their detailed solutions, designed to enhance understanding and prepare students for examination success.

Question 1: Kinematics

A car accelerates uniformly from rest to a speed of 25 m/s over a distance of 100 meters. Calculate the car's acceleration and the time taken to reach this speed.

To find acceleration (a), we can use the equation: ( v^2 = u^2 + 2as ), where ( v ) is the final velocity, ( u ) is the initial velocity, and ( s ) is the distance. Here, ( v = 25 ) m/s, ( u = 0 ) m/s, and ( s = 100 ) m.

Plugging in the values, we get:

( 25^2 = 0 + 2a(100) Rightarrow 625 = 200a Rightarrow a = 3.125 , ext{m/s}^2 )

To find the time (t), use ( v = u + at ). Rearranging gives: ( t = frac{v - u}{a} = frac{25}{3.125} = 8 , ext{s} ).

Question 2: Electricity and Magnetism

Two charges, +5 µC and -3 µC, are positioned 0.5 m apart. Determine the magnitude of the force experienced by each charge.

We use Coulomb's Law given by: ( F = k frac{|q_1 q_2|}{r^2} ), where ( k = 8.99 times 10^9 , ext{N m}^2/text{C}^2 ), ( q_1 = 5 times 10^{-6} , ext{C}), ( q_2 = -3 times 10^{-6} , ext{C} ), and ( r = 0.5 , ext{m}. )

Calculating the force:

( F = 8.99 times 10^9 frac{|5 times 10^{-6} times (-3 times 10^{-6})|}{(0.5)^2} Rightarrow F = 107.875 , ext{N} )

Question 3: Waves

Calculate the frequency of a wave traveling at 340 m/s with a wavelength of 0.85 m.

Using the wave equation: ( v = f lambda ), where ( v ) is the speed, ( f ) is the frequency, and ( lambda ) is the wavelength, we can rearrange to find frequency: ( f = frac{v}{lambda} ).

Calculating gives:

( f = frac{340}{0.85} approx 400 , ext{Hz} )

Conclusion

These three questions cover areas of IB physics, such as kinematics, electricity, and wave phenomena. The detailed solutions provided aim to illustrate the step-by-step approach necessary for solving problems. Practicing with such questions not only prepares students for their exams but also deepens their understanding of the underlying physics concepts.