Answer:
4miles/hour
Explanation:
the solution for this question requires that the quantities are converted to the appropriate units as required by the question.
Rate in miles per hour = distance in miles / time in hour
to convert 12 minutes to hours; recall that 60 minutes make 1 hour
12 minutes to hour = 12/60 = 0.2hr
to convert 4224 feet to miles; recall 5280 feet is equivalent to 1 mile
4224 feet to miles = 4224/5280 = 0.8 miles
∴ rate = 0.8 / 0.2
rate = 4 miles per hour
the constant rate in miles per hour = 4 miles/hour
The amount of power change if less work is done in more time"then the amount of power will decrease".
<u>Option: B</u>
<u>Explanation:</u>
The rate of performing any work or activity by transferring amount of energy per unit time is understood as power. The unit of power is watt
Here this equation showcase that power is directly proportional to the work but dependent upon time as time is inversely proportional to the power i.e as time increases power decreases and vice versa.
This can be understood from an instance, on moving a load up a flight of stairs, the similar amount of work is done, no matter how heavy but when the work is done in a shorter period of time more power is required.
<span>First question: The type of energy involved when a river moves sediment and erodes its banks is: option d. Kinetic energy. Kinetic energy is the energy associated with motion. A body (in this case the water) that moves has an energy associated with its motion that is proportional to the speed (exactly to the square of the speed). When the water collides with the banks it is the kinetic energy of the river that erodes it Second question: the answer is the option d. As gravity pulls water down a slope potential energy changes to knietic energy. This is the, water loses altitude and gains velocity. The potential energy. which is proportional to the height, decreases and the kinetic energy, which is proportional to the square of the speed, increases.</span>
