Answer:
Force, F = 1 N
Explanation:
We have
Mass of a box is 1 kg
Acceleration with which it is pushed is 1 m/s²
It is required to find the force acting on the box.
Force, F = ma

So, the force of 1 N is acting on the box.
As a ball rolls ... even if there were no air resistance ... the ball
has to push down and climb over every one of those little fibers
that stick up from the felt fabric on the table. As it does that, each
little fiber brushes against the ball, and robs a tiny tiny bit of its
kinetic energy.
Answer:
1. D. They can be a substance, material, object or source of energy.
2. B. The properties will be different.
3. C. When two reactants form one product, the reaction is spontaneous.
Answer:
Pressure of the gas is greater than the vapor pressure, therefore all the solid will not sublime.
Explanation:
To solve this problem we use ideal gas equation.
PV =nRT
If Presure of the gas (P) is greater than vapor pressure (56.5 atm), all the solid will not sublime. But If P < 56.5 atm, all of it will sublime.
where;
P is pressure of the gas in atm
V is volume of gas in Litre
T is absolute temperature of the gas in Kelvin
n is number of gas moles
R is ideal gas constant or Boltzmann constant = 0.082057 L atm K⁻¹ mol⁻¹
Given T = 20 °C = 273 + 20 = 293K
Volume = 0.25L
n = Reacting mas (m)/Molar mass(M)
Molar mass of CO₂ = 12 + (16X2) = 12+32 = 44g/mol
Reacting mass = 10g
n = m/M ⇒ 10/44
n = 0.2273
PV =nRT ⇒ P = nRT/V
P = (0.2273X0.082057 X293)/0.25
P = 21.8596 atm
Therefore, since Pressure of the gas is greater than the vapor pressure, all the solid will not sublime.
Answer:
D. Steel is made of different compounds distributed unevenly.
Explanation:
The statement that will support her claim that steel is a homogenous mixture is that steel is made up of different compounds distributed unevenly.
- Steel is an alloy of carbon and iron in its composition.
- Alloys are classified as mixtures.
- Their constituent reacts differently to changed medium.
- The iron in steel does not chemically bond with the carbon.