Question

study the speed time graph of a body given below and answer the following question...
1. what is retardation at 40 seconds
2. what is the distance travelled by the body in last 20 seconds
3. what is the average speed of the body

Answer 1

1- Solve

Retardation = ?
Time = 40Sec
V = 0 M/Sec
U = 40M/Sec

V=U+AT
0=40+A×40
0=40+40A
40A = -40
A = -1M/Sec²

2-Solve

S=?
Time =20Sec
V= 40M/Sec
U= 0M/Sec
A=?

For Finding Acceleration

V=U+AT
40=0+A×20
40 = 20A
20A = 40
A = 2M/Sec²

Now For. Finding Distance

V²=U²+2AS
(40)² = 2×2*S
1600 = 4S
4S = 1600
S = 400Meter Ans

3- Solve

Total Speed = Total Distance / Total Time

Total Speed = 400/40
= 10M/Sec Ans