Vectors and scalars
Which of these is a scalar: force, displacement, speed, or velocity?
Speed
What is the formula for density?
Density = Mass ÷ Volume
What is acceleration?
Rate of change of velocity
Speed in a direction
Velocity
The amount of matter in an object is called?
Mass
What two things must be specified to describe a vector completely?
Magnitude and direction
What is the SI unit of density?
kg/m³ or g/cm³
What is the SI unit of acceleration?
Meters per second squared (m/s²)
Calculate how far an object travels in 5 s if its average speed is 20m/s
100 m
Force due to gravity
Weight
A student walks 50 m north and 50 m south. What are their distance and displacement?
Distance = 100 m, Displacement = 0 m
A metal block has a mass of 200 g and a volume of 50 cm³. What is its density?
4 g/cm³
On a velocity–time graph, what does the slope (gradient) represent?
Acceleration
A car moves 60 km east in 2 hours. What is its velocity?
30 km/h east
An object has mass of 100 kg on earth, what is its weight?
980N
A student walks 4 m east, 3 m south, and then 4 m west. Calculate their resultant displacement.
3 m south
An object has a mass of 6 kg and a density of 3,000 kg/m³. Find its volume.
0.002 m³
A car increases velocity from 10 m/s to 30 m/s in 4 seconds. Find the acceleration.
5 m/s²
A train travels 200 m in 10 s, then 300 m in 20 s. What is its average speed for the entire trip?
16.7 m/s
An astronaut has a mass of 60 kg. Calculate their weight on:
Earth (g = 9.8 m/s²)
Moon (g = 1.6 m/s²)
Earth: 588 N (60 × 9.8)
Moon: 96 N (60 × 1.6)
A drone flies 100 m north, then 100 m east in 20 seconds total
7.07 m/s
A wooden cube of side 0.1 m has a mass of 0.6 kg. Will it float or sink in water (density = 1000 kg/m³)?
It will float.
Density = 0.6 ÷ 0.001 = 600 kg/m³ < 1000 kg/m³, so it floats
A velocity–time graph shows an object moving at 10 m/s for 3 s, then accelerating uniformly to 25 m/s over the next 4 s.
Calculate:
The total distance travelled.
95 m
A runner covers 100 m east in 10 s, then 60 m west in 6 s. Calculate:
Average speed
Average velocity
Total distance = 100 + 60 = 160 m; total time = 16 s → average speed = 10 m/s
Displacement = 100 − 60 = 40 m east → average velocity = 40 ÷ 16 = 2.5 m/s east
A satellite has a weight of 1200 N on Earth. What is its mass? What would be its weight on a planet where g = 15 m/s²?
Mass = 1200 ÷ 9.8 ≈ 122.45 kg
Weight on planet = 122.45 × 15 ≈ 1837 N