Sample Questions by yH3oXX

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									Sample Questions
Which of the following are proper
units for acceleration?
        a)   N
        b)   Kg m/s2
        c)   N/m2
        d)   m/s2
        e)   m2/s
The speedometer of a car
indicates a constant speed.
Can the car be accelerating?
      a) Yes
      b) No
A body falls from rest. If air
resistance is negligible, what
is the velocity of the body after
falling for 10 seconds?
     a)   10 m/s
     b)   9.8 m/s
     c)   98 m/s
     d)   0.98 m/s
     e)   490 m/s
A rifle is fired straight downward from
a high-altitude balloon. If the bullet
leaves the barrel at 100 m/s, then its
speed one second later (neglecting
air resistance) will be about
      a)   9.8 m/s
      b)   98 m/s
      c)   104.9 m/s
      d)   109.8 m/s
What is the acceleration of a
rock at the top of its trajectory
when thrown straight up?
      a)   0 m/s2
      b)   4.9 m/s2
      c)   9.8 m/s2
      d)   4.9 m
      e)   9.8 m
What is the velocity of a rock
at the top of its trajectory
when thrown straight up?
        a)   0 m/s
        b)   4.9 m/s
        c)   9.8 m/s
        d)   490 m
        e)   9.8 m
Which of the following balls would hit
the ground first if they were all
dropped at the same time from the
same height (10 ft) in a vacuum?
       a)   15-lb feather ball
       b)   20-lb wood ball
       c)   10-lb lead ball
       d)   They all it at the same time
The two measurements
necessary for calculating
acceleration are
a)   Velocity and Time
b)   Distance and Time
c)   Distance and Acceleration
d)   Velocity and Distance
What is the acceleration of a vehicle
that changes is velocity from 10m/s
to a dead stop in 10 seconds?

       a)   -1 m/s2
       b)   -100 m/s2
       c)   -0.01 m/s2
       d)   0 m/s2
You throw a ball straight up.
On the way up…
a) the velocity and acceleration both have an
   upward direction
b) the velocity has an upward direction and the
   acceleration has a downward direction
c) the velocity and acceleration both have an
   downward direction
d) the velocity has an downward direction and
   the acceleration has a upward direction
  Attendance check – write your name and the answer to
  this question on a piece of paper and hand it in
What is the instantaneous velocity of
a freely falling object 10 s after it is
released from a position of rest?
   v = at          v = ??
   a = 9.8 m/s2
   t = 10 s
   v = (9.8 m/s2)(10 s) = 98 m/s
How far will it fall during this
time?
  d = do + vot + ½at2     d = ??
  do = 0      vo = 0
  a = 9.8 m/s2
  t = 10 s
  So, d = ½(9.8 m/s2)(10 s)2 = 490 m
What is the average velocity
during this 10-s interval?
  vavg = (vf – vo)/2
  vo = 0 m/s
  vf = 98 m/s
  vavg = (98 m/s – 0 m/s)/2 = 49 m/s
What is the acceleration of a vehicle
that changes its velocity from 0 m/s
to 50 m/s in 10 s?
     a = (vf – vo)/Dt
     vo = 0 m/s
     vf = 50 m/s
     Dt = 10 s
      a = (50 m/s – 0 m/s)/(10 s) = 5 m/s2
Surprisingly, very few athletes can jump
more than 2 feet (0.6m) straight up.
What is the “hang time” for this jump?
     d = ½at2 gives the time to fall
     d = 2 ft
     a = 32 ft/s2

        2d    2(2ft)
     t            2
                       0.35 s
         a   32ft/s
     Total time in the air = 0.7 s
An airplane is flying at 350 mph SW while in the
jet stream, which is blowing at 100 mph from
west to east. What is the speed and direction of
the plane with respect to the ground?




           100 mph W
Add the following forces

        30°
                         60°

                  50 N



 50 N
Free Body Diagrams
A football is moving upwards towards
its peak after having been booted by
the punter. A free-body diagram for
this situation looks like this:
A skydiver is descending with a
constant velocity. Consider air
resistance. A free-body diagram for
this situation looks like this:
A car is coasting to the right and
slowing down. A free-body diagram
for this situation looks like this:

								
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