40 km/h because the average of 50 and 30 is 40
Explanation:
The total resistance Rt is given by
1/Rt = 1/Ra + 1/Rb + 1/Rc = 1/5 + 1/4 + 1/7 = 0.593
or Rt = 1.69 ohms
The total current I running through the circuit is
I = V/Rt = 2.37 A
Explanation:
Given that, the height of the tide measured at a seaside community varies according to the number of hours t after midnight. The height is given by the equation as :

When the tide first be at 6 ft, put h = 6 ft in above equation as :


On solving the above equation to find the value of t. It is equal to :
t = 3.551 seconds
or
t = 8.449 seconds
So, the tide of 6 ft is at 3.551 seconds and 8.449 seconds. Hence, this is the required solution.
Answer:
b) Expansion
Explanation:
In science, matter can be defined as anything that has mass and occupies space. Any physical object that is found on earth is typically composed of matter. Matter are known to be made up of atoms and as a result has the property of existing in states.
Generally, matter exists in three (3) distinct or classical phases and these are; solid, liquid and gas.
A physical change can be defined as a type of change that involves an increase or decrease in the volume of a physical object (object). Also, this change can be reversed to the original state under certain conditions.
The increase in volume of matter that occurs when matter is heated causes an expansion.
This ultimately implies that, when a physical object (matter) is heated for a specific period of time, it result in an increase in the volume of the object; this phenomenon is generally referred to as expansion.
On the other hand, a decrease in volume of a physical object (matter) as a result of heat is known as contraction.
Thes are all correct :<span>2.Scientists observe natural events occurring around them. They question these observations and investigate them.
3.All scientists follow one scientific method of investigation
4.If a hypothesis is not verified by the results from the scientific method, scientists may either redo the process or create a new hypothesis.</span>