The sun’s energy is most useful to humans after it is converted to chemical energy. Living organisms like humans and animals could not directly utilize the energy from the sun because of lack in organs that would allow photosynthesis. Humans and animals obtain the energy from the sun from the intake of food. These foods contain chemical energy which is obtained from the solar energy of the sun. Plants use solar energy for photosynthesis which converts the energy into chemical energy. Then, animals and humans eat the plants obtaining the chemical energy which can readily processed by the body as compared to solar energy.
Answer:
a) F = 2250 Ib
b) F = 550 Ib
c) new max force ( F newmax ) = 2850 Ib
Explanation:
A) The force the wall of the elevator shaft exert on the motor if the elevator starts from rest and goes up
max capacity of elevator = 24000 Ibs
counterweight = 1000 Ibs
To calculate the force (F) :
we first calculate the Tension using this relationship
Counterweight (1000) - T = ( 1000 / g ) ( g/4 )
Hence T = 750 Ib
next determine F
750 + F - 2400 = 2400 / 4
hence F = 2250 Ib
B ) calculate Tension first
T - 1000 = ( 1000/g ) ( g/4)
T = 1250 Ib
F = 2400 -1250 - 2400/ 4
F = 550 Ib
C ) determine design limit
Max = 2400 * 1.2 = 2880 Ib
750 + new force - 2880 = 2880 / 4
new max force ( F newmax ) = 2850 Ib
Answer:
The frequency of sound heard by the boy is 1181 Hz.
Explanation:
Given that,
Frequency of sound from alarm 
Speed = -8.25 m/s
Negative sign show the boy riding away from the car
Speed of sound = 343
We need to calculate the heard frequency
Using formula of frequency

Where,
= frequency of source
= speed of observer
= speed of source
= speed of sound
Put the value into the formula

here, source is at rest


Hence, The frequency of sound heard by the boy is 1181 Hz.
This is a list of well known characteristics of acids:
1) acids increase the concentration of hydronum ions ([H3O+]) when dissolved in water
2) acids taste sour
3) many are corrosive (the higher the acidity the higher the corrosive property)
4) when acids react with some metals produce hydrogen gas
5) acids conduct electricity (due to the presence of hydronium ions)
6) acids neutralize bases
7) acids combine with bases to produce water and salt
8) acids lower the pH of solutions.
They do not feel sticky to the touch. Bases fell slippery but there is not that property of sticky sensation about acids, although some highly concentrated strong acids have high viscosity. You cannot touch highly concentrated strong acids.