Answer:
a physical change
Explanation:
after the water turns to ice, it will melt and became water again making which means it's reversible this being. a physical change
Objects should be cooled before their mass is determined on a sensitive balance because it could damage the balance. Also, because it would give you wrong reading of the mass. Hot objects would warm the air around it. A warm air would expand and would produce convection as it rises causing to give the object a mass that is less than the actual. Another reason would be it would cause instability in the readings, the mass would fluctuate every now and then due to the convection currents around the object. It is always recommended to weigh the masses of objects that are in room temperature.
Answer:
The block will not move.
Explanation:
We'll begin by calculating the frictional force. This can be obtained as follow:
Coefficient of friction (µ) = 0.6
Mass of block (m) = 3 Kg
Acceleration due to gravity (g) = 10 m/s²
Normal reaction (R) = mg = 3 × 10 = 30 N
Frictional force (Fբ) =?
Fբ = µR
Fբ = 0.6 × 30
Fբ = 18 N
From the calculations made above, the frictional force of the block is 18 N. Since the frictional force (i.e 18 N) is bigger than the force applied (i.e 14 N), the block will not move.
The answer is weak.
The interaction of nature that will depend on the distance through the
way it acts and involved in beta decay is the weak interaction or the weak
force. This interaction is the responsible for radioactive decay which also
plays a significant role in nuclear fission.
-- Bob covered a distance of (32m + 45m) = 77 meters.
-- His displacement is the straight-line distance and direction
from his starting point to his ending point.
The straight-line distance is
D = √(32² + 45²)
D = √(1,024 + 2,025)
D = √3,049 = 55.22 meters
The direction is the angle whose tangent is (32/45) south of east.
tan⁻¹(32/45) = tan⁻¹(0.7111...) = 35.42° south of east.
