Mechanical Concepts & Principles

Identify the Distance & Displacement from Home to Shop.

• Distance: 220m

  Displacement: 130m

• Distance: 220m

  Displacement: 220m

• Distance: 130m

  Displacement: 220m

• Distance: 130m

  Displacement:130m

You walk from home to the shop (blue line) in 100 seconds. Calculate your average speed.

• 220m/100s

  = 2.2m/s²

• 220m/100s

  = 2.2m/s

• 130m/100s

  = 1.3m/s²

• 130m/100s

  = 1.3m/s

You forgot to bring your wallet, so you walk the same route (blue line) back to home in 120 seconds.

Calculate your average velocity (to and fro).

• (220m + 220m) / (100s + 120s)

  = 2m/s East

• (220m + 220m) / (100s + 120s)

  = 2m/s West

• (130m + 130m) / (100s + 120s)

  = 1.18m/s West

• 0m / (100s + 120s)

  = 0m/s

What is Usain Bolt's velocity at 40m? Provide your answer in 2 decimal points.

(Velocity = Change in Displacement / time interval)

Answer explanation

40m / (1.96s + 1.02s + 0.90s + 0.88s)

= 8.40 m/s

Usain Bolt's velocity at 40m & 80m are as follow:

Velocity @ 40m: 8.40 m/s

Velocity @ 80m: 9.76 m/s

He took 3.44 seconds between 40m to 80m. Calculate his acceleration.

• 0.40 m/s

• 0.40 m/s²

• 0.44 m/s

• 0.44 m/s²

Answer explanation

Final Velocity = 9.76 m/s

Initial Velocity = 8.40 m/s

Time Taken = 3.44 s

(0.88s + 0.85s + 0.85s + 0.86s)