1.) equal volume of different substances have "different" masses.
2.)The more closely packed arrangement the particles of a substance have, "increases" its density.
3.)the SI unit of power is "Watts".
4.)an iron nail sinks in water but floats on " mercury ".
5.)balloons used for advertisements are filled with " helium" gas.
6.)"Conduction" is the primary mode of heat transfer in liquid and gases.
I hope this helps you...
Answer:
1.65
Explanation:
The equation of the forces along the horizontal direction is:
(1)
where
F = 65 N is the force applied with the push
is the frictional force
m = 4 kg is the mass
is the acceleration
The force of friction can be written as 
(2), where
is the coefficient of kinetic friction
R is the normal force exerted by the floor
The equation of forces along the vertical direction is
(3)
since the bookcase is in equilibrium. Substituting (2) and (3) into (1), we find
And solving for ,
Answer:
v = 21.03 m/s
Explanation:
given,
mass of skier = 45 kg
the slope of the snow = 10.0◦
coefficient of friction = 0.114
distance traveled = 300 m
speed = ?
Acceleration = g sin θ - µ g Cos θ
= 9.8 × Sin (10°) - 0.10 × 9.8 × Cos(10°)
= 0.737 m/s²
using equation of motion
v² = u² + 2 a s
v² = 0 + 2 × 0.737 × 300
v = 21.03 m/s
Speed of skier's after travelling 300 m speed is equal to 21.03 m/s
Answer: Neon is a colorless gas at room temperature: Physical property
At room temperature, mercury is a liquid: Physical property
Apple slices turn brown when exposed to air: Chemical property
Phosphorus will ignite when exposed to air: Chemical property
Explanation:
Physical property is defined as the property of a substance which becomes evident during physical change in which there is alteration in shape, size etc. No new substance gets formed during physical change.
Example: Neon is a colorless gas at room temperature
At room temperature, mercury is a liquid.
Chemical property is defined as the property of a substance which becomes evident during chemical change in which a change in chemical composition takes place. A new substance is formed in these reactions.
Example: Apple slices turn brown when exposed to air: It undergoes oxidation which is a chemical change
Phosphorus will ignite when exposed to air: It undergoes oxidation which is a chemical change
Pb, if compared to Ca it is less reactive and it is a transition metal, and is highly stable alone.
