Question

19. An object starting from rest travels 20 m in first 20 s and 160 m in next 4 s. What will be the velocity after 7 s from the start?

Answer 1

Explanation:

Distance in 20 seconds

s=0∗20+a×20

2

/2

s=200a --(1)

distance travels in first 10 seconds

s

1

=0×10+a×10

2

/2

s

1

=50a --(2)

distance travels in next 10 seconds

s

2

=s−s

1

s

2

=200a−50a=150a--(3)

s

1

s

2

=

50a

150a

=3