physics section 1- motion and forces🔭

• What is the difference between a scalar quantity and a vector quantity?

  A scalar has magnitude only; a vector has magnitude and direction.
• How does velocity differ from speed?

  Velocity includes direction; speed does not.
• What happens to displacement if you walk 5 m north and then 5 m south?

  Displacement is 0 m; distance is 10 m.
• What is the formula relating distance, speed, and time?

  Distance = speed × time.
• What is the average speed of a sprinter who runs 200 m in 25 s?

  8 m/s.
• What is uniform acceleration?

  Acceleration at a constant rate.
• How is acceleration defined?

  Change in velocity over time.
• How do you calculate average acceleration?

  Using the formula: $a =$$(v - u) / t$.
• What does deceleration mean?

  Negative acceleration; slowing down.
• If a car travels at 15 m/s and stops in 1 s, what is its deceleration?

  -15 m/s².
• What is the acceleration due to gravity near Earth's surface?

  Approximately 10 m/s².
• How do you calculate the final velocity using uniform acceleration?

  Using the formula: $v² =$$u² +$$2ax$.
• If a van decelerates from 23 m/s at 2.0 m/s² over 112 m, what is its final speed?

  9 m/s.
• What does a flat section on a distance/time graph indicate?

  The object is stopped.
• What does a steeper graph on a distance/time graph indicate?

  The object is moving faster.
• How can you find speed from a distance/time graph?

  By calculating the gradient of the line.
• How do you find the average speed of an object with non-uniform motion?

  Divide total distance by total time.
• What does a tangent to a curve on a distance/time graph represent?

  The speed at that specific time.
• What are the key features of distance/time graphs?

  • Gradient indicates speed.
  • Flat sections indicate stopping.
  • Steeper graphs indicate faster motion.
  • Curves represent acceleration.
  • Steeper curves indicate speeding up.
  • Leveling off curves indicate slowing down.
• What are the key features of velocity/time graphs?

  • Positive gradient indicates acceleration.
  • Negative gradient indicates deceleration.
  • Flat sections indicate constant velocity.
  • Area under the graph represents distance travelled.
• What is the speed of sound in air?

  340 m/s.
• What is the typical speed of a car in a built-up area?

  13 m/s (47 km/h).
• What is the typical speed of an aeroplane?

  250 m/s (900 km/h).
• What is the typical speed of a train?

  Up to 55 m/s (200 km/h).
• What is the typical speed of a cyclist?

  5.5 m/s (20 km/h).
• What is the typical speed of a runner?

  3 m/s (11 km/h).
• What is the typical speed of a person walking?

  1.4 m/s (5 km/h).
• What is the typical wind speed?

  5-20 m/s.
• What is the typical speed of a ferry?

  15 m/s (54 km/h).
• What is the formula for calculating height from speed just before hitting the ground?

  Height = $v² / (2g)$.
• What is the significance of understanding motion and forces?

  It is vital for understanding physics concepts.
• How can you determine when to use the equation for uniform acceleration?

  By listing the information given in the problem.
• What is the average speed of a cyclist who travels 150 m in 30 s?

  5 m/s.
• How do you sketch a distance-time graph for an object that accelerates, then travels at a steady speed, and then comes to a stop?

  Draw a curve, then a straight line, then a flat line.
• What is the formula for average speed?

  Average speed = distance ÷ time.
• What does a negative gradient on a velocity/time graph indicate?

  Deceleration of the object.
• What does a positive gradient on a velocity/time graph indicate?

  Acceleration of the object.
• What does a flat section on a velocity/time graph indicate?

  Constant velocity of the object.
• What does the area under a velocity/time graph represent?

  Total distance travelled by the object.
• How can you interpret the motion of an object from a velocity/time graph?

  By analyzing the gradients and areas under the graph.