D.Atoms can be divided into smaller parts.
Dalton's atomic theory was the first complete attempt to describe allmatter in terms of atoms and their properties. Dalton based his theory on the law of conservation of mass and the law of constant composition. The first part of his theory states that allmatter is made of atoms, which are indivisible.
If the light is traveling straight up, then it hits the interface (surface
or boundary) between water and air perpendicularly (90° to the surface).
This direction is the direction of the 'normal' to the surface. So the
angle of incidence is zero, and that means the angle of refraction is
also zero. The light just keeps going in the same direction when it
emerges into the air, and is not bent.
However, its speed increases in air, and that means its wavelength
also becomes longer than it was in the water.
Why: As the steel ball rolls uphill, the velocity gradually decreases and finally the ball stops, thus, the acceleration will be in the opposite direction of motion (that is downhill). After the stop, the ball will start rolling downhill by an increasing velocity, thus, the acceleration in this case will be in the same direction as the motion (downhill again).
Answer:
0.6983 m/s
Explanation:
k = spring constant of the spring = 0.4 N/m
L₀ = Initial length = 11 cm = 0.11 m
L = Final length = 27 cm = 0.27 m
x = stretch in the spring = L - L₀ = 0.27 - 0.11 = 0.16 m
m = mass of the mass attached = 0.021 kg
v = speed of the mass
Using conservation of energy
Kinetic energy of mass = Spring potential energy
(0.5) m v² = (0.5) k x²
m v² = k x²
(0.021) v² = (0.4) (0.16)²
v = 0.6983 m/s
The force he must exert is 300 N
