You are practicing throwing darts in your dorm. You stand 3.0 m from the wall on which the board hangs. the dart leaves your hand with a horizontal velocity at a point 2.0 m above the ground. The dart strikes the board at a point 1.65 m from the ground. Calculate:
a) the time of flight of the dart;
b) the initial speed of the dart;
c) the velocity of the dart when it hits the board.
SOLUTION:
THINK:
Horizontal distance, 
Initial height, 
Final height, 
Acceleration due to gravity, 
RESEARCH:
(a)
Vertical displacement, 
Here,
Initial velocity in vertical direction, 
Acceleration, 
(b)
Initial velocity in horizontal direction = Final velocity in horizontal direction

Horizontal range, 
(c)
Vertical component of final velocity, 
Magnitude of velocity on hitting the board, 
SIMPLIFY:
(a)
Vertical displacement, 

(b)
Initial velocity, 
(c)
Vertical component of final velocity, 

Magnitude of velocity on hitting the board, 

CALCULATE:
(a)
Time of flight of the dart, 

(b)
Initial velocity of the dart, 

Magnitude of velocity on hitting the board:
ROUND:
After rounding to two significant figures, we get
(a)
Time of flight of the dart, 
(b)
Initial velocity of the dart, 
(c)
Magnitude of velocity on hitting the board, 