A car travels 140 miles in 3 hours. What is its velocity?

Suppose that the voltage across the resistor is held constant at 40 volts. If the resistance is steadily decreasing at a rate of

hjlf

Answer:

The current is increasing at a rate of 0.32 ampere per second.

Explanation:

The voltage of the resistor is modelled after Ohm's Law, which states that voltage is directly proportional to current:

$V = i\cdot R$ (1)

Where:

$V$ - Voltage, measured in volts.

$i$ - Current, measured in amperes.

$R$ - Resistance, measured in ohms.

An expression for the rate of change in voltage is found by Differential Calculus:

$\frac{dV}{dt} = \frac{di}{dt}\cdot R +i\cdot \frac{dR}{dt}$

$\frac{dV}{dt} = \frac{di}{dt}\cdot R + \frac{V}{R}\cdot \frac{dR}{dt}$ (2)

Where:

$\frac{dV}{dt}$ - Rate of change in voltage, measured in volts per second.

$\frac{di}{dt}$ - Rate of change in current, measured in amperes per second.

$\frac{dR}{dt}$ - Rate of change in resistance, measured in ohms per second.

If we know that $\frac{dV}{dt} = 0\,\frac{V}{s}$ , $R = 5\,\Omega$ , $V = 40\,\Omega$ and $\frac{dR}{dt} = -0.2\,\frac{\Omega}{s}$ , then the rate of change in current is:

$5\cdot \frac{di}{dt}-1.6 = 0$ (3)

$\frac{di}{dt} = 0.32\,\frac{A}{s}$

The current is increasing at a rate of 0.32 ampere per second.

5 0

3 years ago

What is the heat source for rock formation

Otrada [13]

Answer:

Explanation:

The heat source for rock formation

Primordial heat: Some heat accumulated during the earth's formation and it is still available to drive the internal heat Engine of the earth. Some of these heat are used to melt rocks and produce magma.

Radioactive sources: Radioactive elements within the earth also serves as heat source for rock formation. Their spontaneous decay produce heat which are sufficient enough to generate enough thermal energy to melt and produce rocks.

6 0

4 years ago

A soapbox derby is to be held on a frictionless hill with a 28 m vertical drop. The track is 300 m long. What is

ki77a [65]

Answer: -31039 J

Explanation:

5 0

3 years ago

An 18-cm-long bicycle crank arm, with a pedal at one end, is attached to a 20-cm-diameter sprocket, the toothed disk around whic

Tpy6a [65]

Answer:

Part a)