Question

Plot a distance time graph for a body moving at an average speed of 3 metres per second​

Answer 1

a. Area of graph above time axis

A=21×(8−4)×10=60m

Area of graph below time axis

B=21×4×10=20m

Average velocity in whole time of motion

v=TotaltimeDisplacement   = TotaltimeAreaA−AreaB

= 1260−20=3.33ms−1

b. Average speed in whole time of motion

vav=TotaltimeTotaldistance=TotaltimeAreaA+AreaB=1260+20=6.67ms−1

c. Acceleration:

From 0 to 2 s;

a=t2−t1v2−v1=2−010−0=5ms−2

From 2 to 6 s :

a=t2−t1v2−v1=6−210−10=0

From 10 to 12 s: a=t2−t1v2−v1=10−6−10−10=−5ms−2

From 10 to 12 s:

a=t2−t1v2−v1=12−100−(−10)=5ms−2