62.6k views
1 vote
A tennis ball is beaten downward with an initial speed of 5 m/s.

How fast, in m/s, is the ball falling after 3 seconds (neglect air
friction, so g = 9.8 m/s2)?

a 34.4
b 34.4
C 9.8
d 9.8
e 5

2 Answers

7 votes

Answer:

-34.4

Step-by-step explanation:

the person above had the right approach but it would be negative as it is in a downwards motion

User Daydreaming Duck
by
4.0k points
7 votes

Answer:

34.4m/s

Step-by-step explanation:

Step one:

given data

initial speed u= 5m/s

time t= 3seconds

acceleration due to gravity g= 9.8m/s^2

Required:

the final velocity v

Step two:

applying the first equation of motion

v=u+gt-----------we used + because the ball is falling with gravity

v=5+9.8*3

v=5+29.4

v=34.4

The final velocity is 34.4m/s

User Manzotin
by
3.9k points