Answer:
b) 252 Hz or 260 Hz
c) 0.25 s
Explanation:
b) The frequency of the beats is 4 Hz, and one tuning fork has a frequency of 256 Hz. Therefore, the second tuning fork is either 4 Hz lower or 4 Hz higher.
f = 252 Hz or 260 Hz
c) Period is the inverse of frequency.
T = 1/f
T = 1 / (4 Hz)
T = 0.25 s
1 watt = 1 joule/sec
1800 watts = 1800 joules/sec
(1800 J/sec) x (20 min) x (60 sec/min)
= (1800 x 20 x 60) joules = 2,160,000 joules .
( 2.16 megajoules )
Metals
3/4 of the periodic table
Good conductors of heat and electricity
Malleable
Nonmetals
1/4 of the periodic table
Bad conductors of heat and electricity
Not bendable
Incomplete question.The complete one is here
A runner taking part in the 200m dash must run around the end of a track that has a circular arc with a radius curvature of 30m. The runner starts the race at a constant speed. If she completes the 200m dash in 23s and runs at constant speed throughout the race, what is her centripetal acceleration as she runs the curved portion of the track?
Answer:
Explanation:
Given data
Required
Centripetal acceleration
Solution
According to the motions equation the velocity given by:
The centripetal acceleration is given by:
The FASTER an object moves, the MORE KINETIC ENERGY it has.
The greater the MASS of a moving object, the MORE KINETIC ENERGY it has.
15. Kinetic energy. KE= 0.5 * 2.1 * 30^2= 945
16. Potential energy. PE= 1.5 * 10 * 21= 315
17. Kinetic energy. KE= 0.5 * 1120 * 40^2= 896,000
