A ball is dropped from a height of 20m. If its velocity increases uniformly at the rate 10m/s2 with what velocity and after what

Question

4 years ago

12

time will it strike the ground?

2 answers:

belka [17] · Answer 1 · 2021-12-29T20:23:25+03:00

belka [17]4 years ago

6 0

Answer: 2 seconds

Explanation:

adelina 88 [10] · Answer 2 · 2021-12-29T21:43:48+03:00

Since I've only memorized a couple of formulas for these things, I need to do the time first:

I'll use the formula Distance = (1/2) (acceleration) (time)²

20 m = (1/2) (10 m/s²) (time)²

Time² = (20 m) / (5 m/s²)

Time² = 4 sec²

<em>Time = 2 seconds</em>

Now ...

-- When the ball hits the ground, it has been falling for 2 seconds.

-- Its acceleration has caused its speed to increase by 10 m/s every second.

-- So after 2 seconds, its speed has grown to (2 s) (10 m/s²) = <em>20 m/s</em> .