Table of Contents
- Formulas and Units of Measurement for IGCSE Physics 1.2
- IGCSE Physics 1.2 MCQ EXAM QUESTIONS
- IGCSE Physics 1.2 OPEN ENDED QUESTIONS
Formulas and Units of Measurement for IGCSE Physics 1.2
First are the basic scalar quantities:
- Speed is measured in meters per second(m/s).
- Distance is measured in meters(m).
- Time is measured in seconds(s).
Difference between speed and velocity formulas:
- Average speed = total distance / total time taken
- Velocity = displacement / time
Lastly, displacement, velocity and acceleration:
- Velocity is measured in meters per second(m/s) and can be negative or positive depending on the direction of the object.
- Displacement is measured in meters(m).
- Time is measured in seconds(s).
- Acceleration = Change in velocity / change in time
- Acceleration is measured in meters per second squared(m/s^2).
- Change in velocity can be measured by finding the difference between final velocity and initial velocity.
- Weight = mass x gravitational field strength
- Mass is measured in kilograms(kg)
- Gravitational field strength is 9.81 m/s^2
IGCSE Physics 1.2 MCQ EXAM QUESTIONS
1.2.1
A car travels along a clear 10.0 km section of motorway in 6.0 minutes. It then drives through 3.0 km of roadworks in 3.0 minutes.
Which calculation will give the correct average speed for the journey?
A. 3.0/3.0 = 1.00km/min
B. 10.0/6.0 = 1.67km/min
C. 1.67 + 1.00 = 2.67km/min
D. 13.0/9.0 = 1.44km/min
In this question we have to identify what we are given in order to find the answer. The question asks for the average speed of the journey. We know that in order to find average speed, we have to find the total distance and the total time. Do not be fooled into thinking that you have to find the speed of each section that the car travels and find the average of that. All we have to do is 10 + 3 giving us 13 km for the total distance and 6 + 3 giving us 9 mins for the total time. If we use the average speed formula we get 13 / 9 which is clearly option D.
1.2.2
During a Go Karting race, a car does 8 laps of a 300m course. It takes 4.0 minutes to complete the race.
What was the average speed of the Go Kart?
A. 75m/s
B. 10m/s
C. 1.25m/s
D. 600m/s
This question is similar in that it asks for the average speed. So repeating the same methods, we have to first find the total distance and the total time. We are given the length of the course and the time it takes to complete the entire race. But be careful, the question says that it takes 3 minutes to complete the RACE, not the course.
It says that the car did 8 laps which means that the total distance is 300 * 8 = 2400 m. Now we can get the average speed which is 2400m / 4 mins. But hold on, the options give the unit of measurement as m/s not m/mins. This means that 4 minutes has to be converted to 4 * 60 which is 240 seconds. Putting all of this together, we get 2400m / 240s which is equal to 10 m/s which is B.
1.2.3
An object is moving with uniform deceleration. Which statement describes its motion?
A. Its rate of change of speed is decreasing.
B. Its speed is constant.
C. Its speed is decreasing.
D. Its speed is increasing.
In this question, there are no calculations and more theory. You will see a lot of questions like this in your IGCSE worksheets and tests so let’s see how you can solve them. We know that the object is moving with uniform deceleration. The term uniform(not like a school uniform) means that it is decelerating at a constant rate. However it does not mean that the speed is constant, so we can cross out option B.
We should also cross out option A since it says that the rate of change of speed is decreasing which is not true since only the speed is decreasing. Option D should definitely be eliminated since the question does not even talk about increasing speed. That leaves us with the correct answer, C.
Acceleration of freefall: g = 9.81 m/s^2
Statements that apply about freefall only when air resistance can be ignored:
- No matter the mass, all objects will fall at the same acceleration.
- The speed of a falling object will move at a constant increasing rate.
IGCSE Physics 1.2 OPEN ENDED QUESTIONS
1.2.4
Two stones of different weight fall at the same time from a table. Air resistance can be ignored. What will happen and why?
If you read the previous points about freefall, the answer to what will happen is that both stones will hit the floor at the same time. This is because the acceleration of the freefall is constant. Which means that the mass really does not matter since both of them will have the same increase in speed thus causing them to both land at the same time.
You might forget about the previous topics so here’s a revision.
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