




In these questions, ignore air resistance (why?...
because it makes them much easier!)
and use g=9.8ms^{2} 



1. 

At t=0, a ball is thrown with an
initial velocity of magnitude 15ms^{1}
at 75° to the horizontal (upwards). 

a) 
Calculate the magnitudes of the vertical and horizontal
components of its initial velocity. 

b) 
Calculate the magnitude of the vertical component of velocity of
the ball at t=0.5s. 

c) 
Calculate the magnitude of the vertical component of velocity of
the ball at t=2.0s. 


Which way is the ball moving at this time? 

d) 
What is the magnitude of the horizontal
component of velocity at t=2.0s? 



2. 

A projectile is thrown upwards at 60° to the horizontal with an
initial speed of 30ms^{1}. 


Calculate 

a) 
the time taken for the projectile to return to its starting
height 

b) 
the range of the projectile. 


The range is the horizontal distance moved over a horizontal
surface. 



3. 

A ball is thrown upwards at 50° to the horizontal with an
initial speed of 15ms^{1}. 


Calculate the magnitude of its velocity when it is at its
maximum height. 



4. 

A ball is thrown with a velocity of 25ms^{1}
horizontally. 


Find the magnitude and direction of its velocity after 1.25s
(assuming that the ball has not reached the ground at this time). 



5. 

An arrow is shot horizontally at a target 20m
away. 


The arrow hits a point 19.6cm
vertically below the point it was aimed at. 


Calculate the speed with which the arrow left the bow. 