15. PROJECTILE MOTION
is a two-dimensional motion
It is easier to understand this if the
complete motion is split into two.
The first goes horizontally and the
second moves vertically.
Ignoring air resistance, the body
accelerates vertically downwards and
moves horizontally with uniform velocity.
25. • Launching a Cannon ball
Figure 2 Horizontal and Vertical Velocity of
a Projectile physicsclassroom.com
26. Vertical velocity increases each
second with the pull of gravity in
free fall.
Each second the ball goes 10 m/s
faster than the previous second
and a greater distance.
5 m 10 m/s 1 s
20 m 20 m/s 2 s
45 m 30 m/s 3 s
80 m 40 m/s 4 s
27. Which Coin Hits the Floor First?
Place a coin at the edge of a smooth table so that
it hangs over slightly. Then place a second coin
on the tabletop some distance from the
overhanging coin. Slide the second coin so that it
strikes the overhanging coin and both coins fall to
the floor below. What did you observe. Do you
think the speed of the sliding coin affect its
motion?
33. ASSESSMENT .Write True if the statement is
correct and False if it is incorrect.
_____1. A projectile motion has a constant
velocity in the horizontal direction.
_____2. The path followed by a projectile is
known as hyperbola.
_____ 3. The path of the projectile motion is
called a trajectory.
34. ASSESSMENT .Write True if the statement is
correct and False if it is incorrect.
____ 4. A force acting on a projectile is
gravity.
____ 5. As a projectile travel through air, its
vertical velocity remains the same.
____6. Horizontal velocity changes as a
projectile rises and falls.
_____7. Gravity affects both the horizontal
and vertical component of velocity.
35. ASSESSMENT .Write True if the statement is
correct and False if it is incorrect.
______8. A cannon ball rolling down a slope
is an example of projectile.
______9. Vertical velocity changes as a
projectile rises and falls.
______10. Horizontal velocity has a great
effect on the vertical velocity of a projectile.