Kinematics

• What is the definition of speed?

  Speed is a scalar quantity calculated as Speed = $\frac{Distance \, Travelled}{Time \, Taken}$
• What does the symbol $\Delta$ (delta) represent?

  It represents a change in a quantity.
• How is displacement different from distance?

  Displacement is a vector quantity that measures distance in a particular direction.
• If a car travels 2.5 km in 1 minute and 22 seconds, what is the distance in meters?

  The distance is 2500 m.
• How long is 1 minute and 22 seconds in seconds?

  It is 82 seconds.
• What is the average speed of the car if it travels 2500 m in 82 seconds?

  The average speed is $\frac{2500}{82} \approx 31 \, m/s$.
• Did the driver exceed the average speed limit based on the calculations?

  No, the driver was under the speed limit.
• How can you estimate the distance from home to college?

  By estimating the distance in miles or kilometers.
• If the distance to college is estimated at 6 miles, what is the average speed if it takes 40 minutes?

  The average speed is approximately 10.5 mph.
• How long does it take for the reflected wave to arrive back at the transmitter?

  It takes $1.4 \times 10^{-9}$ seconds.
• What is the speed of the wave if it travels 21 cm in 1.4 times 10^-.9seconds?

  The speed of the wave is $3 \times 10^8 \, m/s$.
• What is the diameter of the circle that a person walks around?

  The diameter is 10 m.
• What is the distance travelled when walking around the circumference of a circle with a diameter of 10 m?

  The distance travelled is approximately 31.42 m.
• What is the total displacement when walking around the circumference of a circle and returning to the starting point?

  The total displacement is 0 m.
• What is the distance travelled if a person walks from A to B along the circumference of a circle?

  The distance travelled is 31.42 m.
• What is the total displacement when a person walks from A to B along the circumference of a circle?

  The total displacement is 10 m.