Transcript Sponge - A golf ball rebounds from the floor and travels

Sponge - A golf ball
rebounds from the floor
and travels straight
upward with an initial
speed of 5.0 m/s.
To what maximum height
does the ball rise?
In curved motion, displacement
is still the straight line from the
starting point to the final
location. This displacement
might not be representative of
the actual direction of velocity
during the motion of the object.
Instantaneous velocity
and instantaneous
acceleration can be found
for an object by finding the
components of the
instantaneous vector.
In these situations of
two-dimensional motion
the x part of the motion
occurs exactly as it
would if the y part
did not exist at all,
and vice versa.
Ex. 1 - In the x direction, a
spacecraft has an initial velocity
component of v0x = +22 m/s and
an acceleration component of
ax = +24 m/s2. In the y direction,
v0y = +14 m/s and ay = +12 m/s2.
Right and upward are positive.
After a time of 7.0 s, find (a) x and
vx, (b) y and vy, and (c) the final
velocity of the spacecraft.
In projectile motion, the
vx is constant (vx = v0x),
ax = 0.
But vy changes because
of the acceleration
due to gravity;
2
ay = 9.80 m/s usually.
Ex. 2 - An airplane flies horizontally
with a constant velocity of +115 m/s
at an altitude of 1050 m. The plane
releases a “care package” that falls
to the ground along a curved
trajectory. Ignoring air resistance,
determine the time required for the
package to hit the ground.
Ex. 3 - Find the
velocity of the
package just
before the it hits
the ground.
Ex. 5 - A placekicker kicks a
football at an angle of
θ = 40.0° above the
horizontal axis. The initial
speed of the ball is v0 = 22
m/s. Find the maximum
height H that the ball attains.
Ex. 6 - Determine
the time of flight of
the football
between kickoff
and landing.
Ex. 7 Calculate the
range R of the
kickoff.
Ex. 8 - A baseball player hits a
home run, and the ball lands in
the left-field seats, 7.5 m above
the point at which the ball was
hit. The ball lands with a
velocity of 36 m/s at an angle of
28° below the horizontal . Find
the initial velocity with which the
ball leaves the bat.