A particle is projected from ground level ,so that it's height above the ground after 't' second is given by (10t-5t×t)meters, after how many seconds is it 15 meter above the ground.?
Answers
Answered by
1
10t-5t*t=0
Use quadratic equation
Use will get
(T-3)(T+1)
Hence time cannot be negative
The answer is t=3s
Use quadratic equation
Use will get
(T-3)(T+1)
Hence time cannot be negative
The answer is t=3s
Answered by
0
Answer:
The particle reaches 15 meters on the way up after 1 second,
and passes 15 meters again after 3 seconds on the way down.
Explanation:
20t-5t^2=15
20t=5t^2+15
0=5t^2-20t+15
0=t^2-4t+3
0=(t-3)(t-1)
t-3=0 or t-1=0
t=3 or t=1
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