What is the sexagesimal system?
The sexagesimal system is a numbering system based on the number 60, historically used by the Sumerians and Babylonians.
Can acceleration be in the opposite direction to velocity?
Yes, when an object is slowing down (negative acceleration).
If a car accelerates from 10 m/s to 30 m/s in 5 seconds, what is its acceleration?
Acceleration = (30 - 10) / 5 = 4 m/s²
What is the definition of a metre in the SI system?
A metre is the distance that light travels in a vacuum in 1/299,792,458 seconds. This redefinition uses a universal constant (the speed of light).
How can you reduce relative error?
Use more precise instruments and take repeated measurements.
What is the formula for density?
(Density = Mass / Volume).
How many milliseconds are in 3 seconds?;
3000 milliseconds
What happens to an object if its density is greater than water (1 g/cm³)?
It sinks.
How is a second in the SI system defined?
The time that elapses during 9,192,631,770 (9.192631770 x 109)cycles of the radiation produced the transition between two levels of a cesium 133 atom.
What is the SI unit of length?
Metre(m).
What happens when acceleration is negative?;
It means the object is slowing down (deceleration).
How does casual error impact scientific experiments?;
It affects the precision of measurements but does not necessarily bias the results.
If a car moves 100 meters north in 5 seconds, what is its velocity?
Velocity = 100 m / 5 s = 20 m/s north
What is the International System of Units?
It is a standardised system of measurement used globally in science and industry.
Where is the sexagesimal system used today?
It is used to measure time (hours, minutes, seconds), angles (degrees, minutes, seconds), and geographical coordinates.
If oil floats on water, is its density more or less than 1 g/cm³?
Less than 1 g/cm³.
What is kinematics in physics?
Kinematics is the branch of physics that deals with the motion of objects without considering the forces causing the motion.
A metal block has a mass of 500 g and a volume of 0.1 m³. What is its density in kg/m³?
5 kg/m³
What is the difference between average acceleration and instantaneous acceleration?
Average acceleration is the change in velocity over a time interval, while instantaneous acceleration is the rate of change of velocity at a specific time.
What is velocity?
Velocity is the speed of an object in a specific direction. It is a vector quantity.
How do you calculate velocity?
Velocity = Displacement / Time
What are the seven base units of the SI?
Meter (m), Kilogram (kg), Second (s), Kelvin (K), Ampere (A), Mole (mol), Candela (cd).
If the true value of an object’s length is 10 cm and the measured value is 9.8 cm, what is the absolute error?
Absolute Error = |10 - 9.8| = 0.2 cm
If you cut a wooden block in half, what happens to its density?
It stays the same.
Why is relative error important in experiments?
It helps to compare the accuracy of different measurements.
Multiply (2 × 10³) by (3 × 10²).
6 × 10⁵
What is the difference between fundamental and derived quantities?
Fundamental quantities are independent (e.g., length, mass, time), while derived quantities are based on them (e.g., speed, force).
A car accelerates from 10 m/s to 40 m/s in 6 seconds. What is its acceleration?
5 m/s² ((40 - 10) ÷ 6)
If you measure an object’s length multiple times and get slightly different values, what type of error is this?
A casual error.
How does the vertical velocity of a projectile change as it moves upward and downward?
The vertical velocity decreases as the projectile moves upward, becomes zero at the peak, and then increases (in the opposite direction) as it falls downward.
Do casual errors have a systematic pattern?
No, they occur randomly and unpredictably.
A cyclist travels at 12 m/s for 30 seconds. What distance do they cover?
360 meters
What is the difference between speed and velocity?
Speed is a scalar quantity that refers to how fast an object moves, while velocity is a vector quantity that includes both speed and direction.
Convert 1.2 hours into minutes.
72 minutes (1.2 × 60)
What is the difference between displacement and distance?
Displacement is the straight-line distance from the initial to the final position, including direction, while distance is the total distance travelled.
Give an example of a scalar quantity.
e.g.Speed (e.g., 60 km/h).
How are casual errors different from systematic errors?
Systematic errors occur due to consistent faults in measurement tools or methods, while casual errors are random.
What is relative error?
Relative error is the ratio of the absolute error to the actual measurement, usually expressed as a percentage.
What is the SI unit of velocity?
Metres per second (m/s).
What does a high relative error indicate?
It indicates a less precise measurement.
What is instantaneous velocity?
Instantaneous velocity is the velocity of an object at a specific moment in time.
Can casual errors be eliminated?
No, but they can be reduced by taking multiple measurements and averaging them.
How does the concept of the “conventional value” of physical constants, such as the speed of light, play a role in the SI system?
The speed of light in a vacuum is fixed at 299,792,458 m/s\ in the SI system. This value is used in definitions of other units, such as the meter.
A liquid has a volume of 200 cm³ and a mass of 160 g. What is its density?
0.8 g/cm³
Give an example of uniform acceleration.
e.g.An object in free fall experiences uniform acceleration (9.8 m/s²) due to gravity.
If a car is moving at a constant velocity, what is its acceleration?
Zero, because velocity is not changing.
What is absolute error?
Absolute error is the difference between the measured value and the true value.
How do casual errors affect experimental results?
They cause variations in repeated measurements, making results less precise.
How do you calculate relative error?
Relative Error = (Absolute Error / True Value) × 100%
What is uniform velocity?
Uniform velocity means an object moves with constant speed in a straight line.
Why do casual errors occur in experiments?
Due to slight variations in environmental conditions, human reaction time, and instrument limitations.
If a runner completes a 400 m race in 48 seconds, what is their average speed?
8.33 m/s (400 ÷ 48)
Convert 0.0003 to scientific notation
3 × 10⁻⁴
What is the relationship between a kilogram and a gram?
1 kilogram (kg) is equal to 1000 grams (g).
What is a good relative error percentage in scientific experiments?;
Typically, a relative error below 5% is considered acceptable.
Does relative error depend on the unit of measurement?
No, since it is a ratio, it remains the same regardless of the unit.
Divide (9 × 10⁸) by (3 × 10²).
3 × 10⁶
Why is the International System important in science?
It provides a universal standard for measurements, ensuring consistency and accuracy in scientific research and industry.
Can velocity be negative?
Yes, if the object moves in the opposite direction to the chosen reference.
Give an example of a casual error.
e.g. Fluctuations in measurements due to differences in observers reaction times.
A liquid has a volume of 200 cm³ and a mass of 160 g. What is its density?
0.8 g/cm³
What happens to velocity when an object changes direction?
The velocity changes because direction is a part of velocity.
Define acceleration in kinematics.
Acceleration is the rate of change of velocity over time, expressed as a=Δv/Δt.
What is the relative velocity of two objects moving in the same direction?
It is the difference between their velocities: V_relative = V_A - V_B.
What is a casual error in physics?
A casual error is an unpredictable/random error that occurs due to unknown factors.