Explanation:
The magnetic needle of a compass lines up with Earth's magnetic poles.
Answer:
- <u>The energy change would be 46kJ</u>
- <u>The energy would be absorbed</u>
Explanation:
The <em>energy change </em>during a chemical reation, i.e. the reaction energy, is equal to the chemical energy stored in the<em> bonds of the products </em>less the chemical energy stored in the <em>bonds of the reactants</em>.
Hence:
- <em>Energy change</em> = 478 kJ - 432kJ = 46kJ
The change is positive, this is, the chemical energy of the products is greater than the chemical energy of the reactants.
That corresponds to the second graph, where the level of the energy of the products in the graph is higher than the level of the energy of the reactants. Therefore, the conclusion is that the reaction <em>absorbed energy</em> and it is endothermic.
Answer:
(d) a net external force must be acting on the system
Explanation:
Momentum is given as the product of mass and velocity.
P = MV
According to Newton's second law of motion, " Force applied to a body (system) is directly proportional to the rate of change of momentum of the body (system) which takes place in the direction of the applied force (external force).
F ∝ΔMV
Therefore, If the total momentum of a system is changing, a net external force must be acting on the system.
(d) a net external force must be acting on the system
Answer:
4 (D): twice the voltage, and the same current will flow through each.
Explanation:
When we have batteries in series in a circuit, the equivalent voltage will be the sum of their voltages, and the current flowing through then will be the same.
These batteries are identical, so they have the same voltage, therefore when they are put in series, the equivalent voltage will be twice the voltage of one battery.
So the correct option is 4 (D): twice the voltage, and the same current will flow through each.
Answer: |F| = 1.28 x 10⁵ N
Explanation:
an impulse results in a change of momentum
FΔt = mΔv
F = m(vf - vi)/t
F = 2000(0 - 32) / 0.5
F = -128,000
|F| = 1.28 x 10⁵ N
