Answer:

Explanation:
Given


Required
Determine the speed of B w.r.t A
The question implies that, we determine the relative velocity of B w.r.t A
Because both trains are moving towards one another, the required velocity is a
both trains:
This is shown below:



Answer:
Explanation:
Units...Nothing is accurate without UNITS. 8.0±0.3 lbs,? Newtons? 3.5±0.2 m²? ft²? cm²? km²? furlong²? fathoms²?
your answer will be 8.0±0.3 / 3.5±0.2 units / units²
Answer:
FAE= 0.014 N
Explanation:
The KE of block is decreased because of the slowing action of the friction force .
Change in KE of block = work done on block by friction ƒ
⠀ ➪ ½mu²ƒ - ½mu²i = Fƒs cos θ
Because the friction force on the block is opposite in direction to the displacement , cos θ = -1
➢ Using Uƒ = 0 , Vƒ = 0.20 m/s , and s = 0.70 m
✒ We find ,
➪½mu²ƒ - ½mu²i = Fƒs cos θ
➪0-½ (0.50 kg) (0.20 m/s)² = (Fƒ) (0.70 m) (-1)
➪ Fƒ = 0.014 N
Hope this helped, can i pls have brainliest
Answer:
The existance of dark energy was suggested to help explain measurements, using Type Ia supernovae as distance indicators, that the expansion of the universe is speeding up and its acceleration requires a source of energy. Scientists suggested that It may be a new form of energy for which there is not yet a theoretical explanation. quantum mechanics predict that it may be the vacuum energy associated with "empty" space itself.
The amount of heat needed to increase the temperature of a substance by

is given by

where
m is the mass of the substance

the specific heat capacity

the increase in temperature
In our problem, the mass of the water is m=750 g, the specific heat is

and the amount of heat supplied is

, so if we re-arrange the previous formula we find the increase in temperature of the water: