ern5231 wrote:Q1)A, B are 100m above the ground and B is dropped 10 sec before A. Which one first reaches the ground?

1) B is 25% faster than A
2) A's speed is greater than 2 m/s

Q2)Lift A and B are 200 feet above the ground, two elevators have a constant rate of decline. B declines 10 sec later than A. Which one first reaches the ground?

I: B's speed is 1 feet / s more than that of A

II: B's speed is 25% more than that of

umaa wrote:

ern5231 wrote:Q1)A, B are 100m above the ground and B is dropped 10 sec before A. Which one first reaches the ground?

1) B is 25% faster than A
2) A's speed is greater than 2 m/s

Q2)Lift A and B are 200 feet above the ground, two elevators have a constant rate of decline. B declines 10 sec later than A. Which one first reaches the ground?

I: B's speed is 1 feet / s more than that of A

II: B's speed is 25% more than that of

Q1: IMO A

Q2: IMO C

Oa pls

fruti_yum wrote:

umaa wrote:

ern5231 wrote:Q1)A, B are 100m above the ground and B is dropped 10 sec before A. Which one first reaches the ground?

1) B is 25% faster than A
2) A's speed is greater than 2 m/s

Q2)Lift A and B are 200 feet above the ground, two elevators have a constant rate of decline. B declines 10 sec later than A. Which one first reaches the ground?

I: B's speed is 1 feet / s more than that of A

II: B's speed is 25% more than that of

Q1: IMO A

Q2: IMO C

Oa pls

to answer this question we need to know the actual speeds of both lifts to work out if the 10secs lag is reversed because of a difference in speed:

B only tells us that B is faster than A but we dont know whether or not the speed advantage is enough to overcome the 10 sec lag.

combining the statement tells us that 1f/s = 25% hence 100% = 4 so A's speed is 4f/s and B's speed is 5f/s which is sufficient to work out the actual times they reach the bottom.

hope that helps.




I dont understand why question 2 is C. IMO B