During a thunderstorm, a frightened child is soothed by learning to estimate the distance to a lightning strike by counting the time between seeing the lightning and hearing the thunder (Fig. P2.25). The speed vs of sound in air depends on the air temperature, but assume the value is 343 m/s. The speed of light c is 3.00 3 108 m/s. a. E A child sees the lightning and then counts to eight slowly before hearing the thunder. Assume the light travel time is negligible. Estimate the distance to the lightning strike. b. N Using your estimate in part (a), find the light travel time. Is it fair to neglect the light travel time? c. C Think about how time was measured in this problem. Is it fair to neglect the difference between the speed of sound in cold air (vs at 0°C 5 331.4 m/s) and the speed of sound in very warm air (vs at 40°C 5 355.4 m/s)?
Displacement, Velocity and Acceleration
In classical mechanics, kinematics deals with the motion of a particle. It deals only with the position, velocity, acceleration, and displacement of a particle. It has no concern about the source of motion.
Linear Displacement
The term "displacement" refers to when something shifts away from its original "location," and "linear" refers to a straight line. As a result, “Linear Displacement” can be described as the movement of an object in a straight line along a single axis, for example, from side to side or up and down. Non-contact sensors such as LVDTs and other linear location sensors can calculate linear displacement. Non-contact sensors such as LVDTs and other linear location sensors can calculate linear displacement. Linear displacement is usually measured in millimeters or inches and may be positive or negative.
. During a thunderstorm, a frightened child is soothed by learning to estimate the distance to a lightning strike by counting the
time between seeing the lightning and hearing the thunder (Fig.
P2.25). The speed vs of sound in air depends on the air temperature, but assume the value is 343 m/s. The speed of light c
is 3.00 3 108
m/s.
a. E A child sees the lightning and then counts to eight slowly
before hearing the thunder. Assume the light travel time is
negligible. Estimate the distance to the lightning strike.
b. N Using your estimate in part (a), find the light travel time.
Is it fair to neglect the light travel time?
c. C Think about how time was measured in this problem. Is it
fair to neglect the difference between the speed of sound in
cold air (vs at 0°C 5 331.4 m/s) and the speed of sound in
very warm air (vs at 40°C 5 355.4 m/s)?
Trending now
This is a popular solution!
Step by step
Solved in 3 steps
