Answer:
1- For the track B. The potential energy is the same for the two cars, but because of the slope of the track, the car B earn kinetic energy faster. The gravitation acceleration of the cars will be g•sinθ, and the angle of the track B will have a bigger value for sinθ
2- The conservation of energy applies because the roller coaster is a closed track. When a car climb the track, it earn GPE, which is given by mgh, when it get down in the track, it transform GPE in KE, which is given in 1/2mv².
3-
Position of car (m) GPE KE GPE + KE
top (30m) 60000 0 60000
bottom (0m) 0 60000 60000
halfway down (15m) 30000 30000 60000
three-quarters way down 15000 45000 60000
use the formula
v= u+ at
v is final velocity , u is initial velocity , a is acceleration and t is time
put the values
20 = 0+ a×5
a = 4 m/s²
Answer:
3 m/s
Explanation:
The slope is distance divided by time, also known as 'speed'.
15 meters / 5 seconds = 3 meters per second.
Answer:
The atom is mostly empty space.
Explanation:
Ernest Rutherford in the year 1911 developed a model of an atom. In his model the atom was shown that the atom is mostly empty spaces composed of negative electrons which orbits round a positive nucleus just like planets revolving round the sun.
Rutherford came up with this model by performing experiments in 1909 which involves the scattering of alpha particles on a thin gold foil. From this experiments he came up with his model.
79 m/s. A stone dropped from the top of the Empire State Building will have a velocity of 79 m/s just before it strikes the ground.
This problem is about free fall, to find the velocity of the stone before it strikes the ground we have to use the equation 
, the initial velocity of the stone is 0 m/s. Then:
Solving the equation above with g = 9.8 m/s², and h = 318.0 m:
≅ 79 m/s
