Question

A particle with uniform acceleration is travelling for 4T seconds. It has an average velocity of 20 m/s for the first T seconds. It has an average velocity of 50 m/s for the last T seconds. What is its average velocity for the middle 2T seconds?

Answer 1

Explanation:

ANSWER

Average velocity =

Δt

s

=v

avg

S=∫

0

5

vdt=∫

0

5

(4t−t

2

)dt=

3

25

m

v

avg

=

5sec

25/3m

=

3

5

sec

m

Average speed =

time taken

distance covered

=

Δt

distance

Distance =∫

0

4

vdt+∫

4

5

(−v)dt=

3

32

+

3

7

=

3

39

m=13m

Average speed =

5sec

13m

Average acceleration (a

avg

)=

Δt

v

f

−v

i

v

f

=4×5−5

2

=20−25=−5

v

i

=0

a

avg

=

5

−5−0

=−1m/s

2