Posted by Megan on Friday, May 25, 2012 at 2:42pm.
by speed, do you mean the vector sum of the horizontal and vertical speeds?
Must be, since the horizontal speed never changes, and the initial vertical speed was 0, so double that is still 0.
v = 4.3i - 9.8tj
|v| = √(4.3^2 + (9.8t)^2) = √(96.04t^2 + 18.49)
so, double the original speed is 8.6m/s and we want to find t when
8.6 = √(96.04t^2 + 18.49)
t = 0.76 sec
This is the projectile thrown with horizontal velocity.
So
v(x) = const,
v(y) = g•t.
v ² = v(x)² +v(y)²
v =2•v(x),
[2v(v)]² = v(x)² +v(y)²,
3•v(x)² =v(y)² = (g•t)²,
t =v(x) •√3/g =4.3•1.73/9.8 =0.76 s.
Related Questions
physics - Sam tosses a ball horizontally off a footbridge at 3.1 m/s. How much ...
physics - Sam tosses a ball horizontally off a footbridge at 3.2 m/s. How much ...
physics - i posted this question before however i did not understand drwls ...
physics - umm i need help...which equation would i use to solve the probnlem ...
physics - A boy reaches out of a window and tosses a ball straight up with a ...
physics - Kevin tosses a 0.10 kg ball horizontally with an initial velocity of ...
Physics - A winning basketball shot in the last second of a game is launched ...
physics - We throw a ball horizontally at 10m/s. (a) after how much time does ...
physics - A boy reaches out of a window and tosses a ball straight up with a ...
physics - You and two friends are on top of the library 30 m above the ground. ...
For Further Reading
