Answer: Volcanoes and ridges are landforms that are created by the movement of tectonic plates.
Explanation:
Density = Mass/Volume
So, given mass = 20 g and volume = 40 cm^3
By substituting in above equation, Density = 20/40 = 0.5 g/cm^3
Hope it helps.
Answer:
Total kinetic energy of entire system is 3 mgl
Explanation:
Given two masses: m and 4m.
Since the pulley is frictionless and the thread is massless, the energy here is linked to the two masses.
Total kinetic energy of entire system = decrease in gravitational potential energy of the system.
Therefore, we have :
ΔKE = Δp
ΔKE = 4mgl - mgl
= 3 mgl
Total kinetic energy of entire system is 3 mgl