physics
posted by Isis .
a ball is thrown up and reaches a maximum height of 5 m.
a) what is the initial velocity of the ball?
b) how long does it take for the ball to reach its maximum height?
c) what is the final velocity of the ball? if i returns to where it was thrown from?

y = y0 + v0*t  1/2*g*t^2
where y0 is the initial height = 0, v0 is the initial speed, and g is the acceleration due to gravity, t is time, and y is the vertical position.
The ball reaches it's maximum height when dy/dt = 0 = v0  g*t
and y = 5, so
5 = v0*t  1/2*g*t^2
Use algebra to find the initial velocity and time.
The final velocity of the ball is given by
1. v = v0  g*t, occurs when y = 0, or when
2. 0 = v0*t  1/2*g*t^2
solve 2nd equation for t, and plug into 1st equation to solve for the final speed v at this time. 
a sandbag is dropped from an unknown height. h, from the ground. if after 5 sec. it is located one half the height from which is thrown , at what height was it dropped?
b. what is its speed after 5 sec.?
c. what is its speed when it strikes the ground?
Respond to this Question
Similar Questions

physics
a ball is thrown at an initial angle of 37 and initail velocity of 23.0 m/s reaches a maximum height h, as shwon in the Figure. With what initial speed must a ball be thrown straight up to reach the same maximum height h? 
physics
a ball is thrown at an initial angle of 37 and initial velocity of 23.0 m/s reaches a maximum height h, as shown in the Figure. With what initial speed must a ball be thrown straight up to reach the same maximum height h? 
phy
A blue ball is thrown upward with an initial speed of 20.6 m/s, from a height of 0.8 meters above the ground. 2.5 seconds after the blue ball is thrown, a red ball is thrown down with an initial speed of 8.2 m/s from a height of 23.7 … 
algebra
A ball is thrown into the air with an upward velocity of 28 ft/s. Its height (h) in feet after t seconds is given by the function h = –16t² + 28t + 7. How long does it take the ball to reach its maximum height? 
physics
A red ball is thrown down with an initial speed of 1.2 m/s from a height of 25.0 meters above the ground. Then, 0.6 seconds after the red ball is thrown, a blue ball is thrown upward with an initial speed of 22.9 m/s, from a height … 
physics
if ball is thrown upward with a initial velocity of 38.5 m/s and the maximum height of the ball is 74.1m. How long will it take the ball to reach it's maximum height 
Physics
A red ball is thrown down with an initial speed of 1.3 m/s from a height of 28.0 meters above the ground. Then, 0.6 seconds after the red ball is thrown, a blue ball is thrown upward with an initial speed of 24.7 m/s, from a height … 
Algebra
A ball is thrown into the air with an upward velocity of 28 ft/s. Its height (h) in feet after t seconds is given by the function h = –16t² + 28t + 7. How long does it take the ball to reach its maximum height? 
math
A ball is thrown into the air with an upward velocity of 20 ft/s. Its height (h) in feet after t seconds is given by the function h(t) = –16t^2 + 20t + 2. How long does it take the ball to reach its maximum height? 
algebra 2
A ball is thrown directly upward from an initial height of 200 feet with an initial velocity of 96 feet per second. After t seconds, the height of the ball above the ground is s(t) = 16t2+ 96t + 200. a. After how many seconds …