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2 years ago

For each of the following systems and time intervals, select the appropriate version of

Physics

1 answer:

Ahat [919]2 years ago

4 0

The heating coils in you toaster during the first five seconds after you turn the toaster on is Δ K = W + Q.

Your automobile just before you fill it with gas until you pull away from the gas station at speed v is ΔK + ΔU + ΔEint = W + Q + TMW + TMT

your body while you sit quietly and eat a peanut butter and jelly sandwich for lunch is ΔEint = Q + TET + TER
 

your home during five minutes of a sunny afternoon while the temperature in the home remains fixed is ΔU = W + Q + TMW + TMT

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a torch bulb is rated 2.5V and 750mA. Calculate its power,its resistance and the energy consumed if this bulb lighted for 4 hour

Hatshy [7]

Using Ohm's Law, we can derived from this the value of resistance. If I=V/R, therefore, R = V/I
Substituting the values to the given,
P = Power = ?
R = Resistance = ?
V = Voltage = 2.5 V
I = Current = 750 mA

R = V/I = 2.5/ (750 x 10^-3)
R = 3.33 ohms

Calculating the power, we have P = IV

P = (750 x 10^-3)(2.5)
P = 1.875 W

The power consumption is the power consumed multiply by the number of hours. In here, we have;
1.875W x 4 hours = 7.5 watt-hours

3 0

2 years ago

If you have to apply 40n of force on a crowbar to lift a rock that weights 400n, what is the actual mechanical advantage of the

Mrrafil [7]

The mechanical advantage is defined as the ratio between the force produced by a machine and the force applied in input:
$MA= \frac{F_{out}}{F_{in}}$
For the crowbar of the problem, the force applied in input is 40 N, while the force produced in output is equal to the weight of the rock that is lifted, so 400 N. Therefore, the mechanical advantage is
$MA= \frac{400 N}{40 N}=10$

3 0

2 years ago

A roller coaster car drops a maximum vertical distance of 35.4 m. Determine the maximum speed of the car at the bottom of that d

marissa [1.9K]

Answer:

The maximum speed of the car at the bottom of that drop is 26.34 m/s.

Explanation:

Given that,

The maximum vertical distance covered by the roller coaster, h = 35.4 m

We need to find the maximum speed of the car at the bottom of that drop. It is a case of conservation of energy. The energy at bottom is equal to the energy at top such that :

$mgh=\dfrac{1}{2}mv^2$

$v=\sqrt{2gh}$

$v=\sqrt{2\times 9.8\times 35.4}$

v = 26.34 m/s

So, the maximum speed of the car at the bottom of that drop is 26.34 m/s. Hence, this is the required solution.

8 0

2 years ago

A 50-kg load is suspended from a steel wire of diameter 1.0 mm and length 11.2 m. By what distance will the wire stretch? Young'

lbvjy [14]

Answer:

3.5 cm

Explanation:

mass, m = 50 kg

diameter = 1 mm

radius, r = half of diameter = 0.5 mm = 0.5 x 10^-3 m

L = 11.2 m

Y = 2 x 10^11 Pa

Area of crossection of wire = π r² = 3.14 x 0.5 x 10^-3 x 0.5 x 10^-3

= 7.85 x 10^-7 m^2

Let the wire is stretch by ΔL.

The formula for Young's modulus is given by

$Y =\frac{mgL}{A\Delta L}$

$\Delta L =\frac{mgL}{A\times Y}$

ΔL = 0.035 m = 3.5 cm

Thus, the length of the wire stretch by 3.5 cm.

5 0

2 years ago

To show that displacement current is necessary to make Ampère's law consistent for a charging capacitor Ampère's law relates the

Sladkaya [172]

Answer: The Ampère -Max-well law

Explanation:

The Ampère -Max-well law relates magnetic flux and electric current. It determines the relationship between current in association with a magnetic field and also magnetic field in association to related current.

7 0

2 years ago