a tennis ball is thrown up and reaches a certain height and comes down in 8s. If value of acceleration due to gravity (g)=10m/s^2 , then height reached by tennis ball and velocity with which it strikes the ground respectively is _______&_______
Answers
Answer:
u = -80 m/s
h = -320 m
Velocity = -40 m/s
Explanation:
Given
u = ?
v = 0
t = 8s
because reaching 8s in downwards so it is equal to
upwards
g = 10 m/s^2
To find u using 1st equation
v = u + gt
0 = u + 10(8)
0 = u + 80
.°. u = -80 m/s
To find h , using 3rd equation
v^2 = u^2 + 2gh
(0)^2 = (-80)^2 + 2(10)h
0 = 6400 + 20h
-20h = 6400
h = 6400/-20
h = - 320 m
Symbol ( - ) is used for against earth's gravity
h = -320 m (displacement)
t = 8s (time taken)
Velocity = displacement/time
= -320/8
Velocity = -40 m/s
If its total velocity means Total velocity =
Total displacement/total time taken
(Final Velocity - Initial Velocity)/ time taken
= (-320 -(-320) ) / 8s + 8s
= (-320 + 320) / 16s
= 0 / 16s
= 0 m/s
Answer:
80m,40m/s
Explanation: