Question

The figure shows the graph of the x-coordinate of a particle going along the X-axis as a function of time. Find (a) the average velocity during $0$ to $10s$, (b)
instantaneous velocity at $2,5,8$ and $12s$.

• A. (a) $10m/s$, (b) $20m/s$, $zero$, $20m/s$, $-20m/s$
• B. (a) $20m/s$, (b) $10m/s$, $zero$, $-10m/s$, $-15m/s$
  
• C. (a) $15m/s$, (b) $15m/s$, $10m/s$, $-15m/s$, $20m/s$
  
• D. (a) $25m/s$, (b) $10m/s$, $-10m/s$, $zero$, $20m/s$
  

Answer 1

Answer: (A)

(a) $10m/s$, (b) $20m/s$, $zero$, $20m/s$, $-20m/s$

Avg. velocity from $0-10=\frac{displacement}{time}=\frac{100}{10}=10m/s$

Instantaneous velocity

at $2.5=$ slope of (1) $=\frac{50}{2.5}=10m/s$

at $5.5=$ slope of (2) $=0m/s$

at $8.5=$ slope of (3) $=\frac{50}{2.5}=20m/s$

at $12.5$ slope of (4) $=\frac{-100}{5}=-20m/s$