Marks: 1
What is the power of a light that uses 300 joules of energy in 60
seconds?
18,000 W
50 W
5 W
0.2 W

Answer:

pressure = force / area

then pressure = 25 / 5 = "5" N/m^2

Explanation:

a) We need to write down first Newton's 2nd law as applied to the given system. The equations of motion for the x- and y-axes can be written as follows:

[tex]x:\;\;\;\;\;mg\sin 25° - \mu_kN = ma\;\;\;\;\;\;(1)[/tex]

[tex]y:\;\;\;\;\;N - mg\cos 25° = 0\;\;\;\;\;\;\;\;\;(2)[/tex]

From Eqn(2), we see that

[tex]N = mg\cos 25°\;\;\;\;\;\;\;(3)[/tex]

so using Eqn(3) on Eqn(1), we get

[tex]mg\sin 25° - \mu_kmg\cos 25° = ma[/tex]

Solving for the acceleration, we see that

[tex]a = g(\sin 25° - \mu_k\cos 25°)[/tex]

[tex]\;\;\;\;= 2.45\:\text{m/s}^2[/tex]

b) Now that we have the acceleration, we can now solve for the velocity of the crate at the bottom of the plane. Using the equation

[tex]v^2 = v_0^2 + 2ax[/tex]

Since the crate started from rest, [tex]v_0 = 0.[/tex] Thus our equation reduces to

[tex]v^2 = 2ax \Rightarrow v = \sqrt{2ax}[/tex]

[tex]v = \sqrt{2(2.45\:\text{m/s}^2)(8.15\:\text{m})}[/tex]

[tex]\;\;\;\;= 6.32\:\text{m/s}[/tex]

Answer:Colloid - well compacted together but not one

Answer:

faster over the left side than over the right side.

Explanation:

due to ball rotation, the right side is more closely matched to the speed of the air passing by as the ball progresses. This causes the air to stick more closely to the right side of the ball and that air stays with the ball surface as the spin moves it to the back of the ball and therefore leftward. As every action has an equal and opposite reaction the leftward force moving air causes the ball to experience an equal rightward force.

When the baseball curves to the right (a curveball), then the ball moves faster over the left side than over the right side.

The ball, which is thrown with a spin, is curve in the direction in which the front of the ball turns.

When a baseball curves to the right (a curveball),

Hence, when the baseball curves to the right (a curveball), then the ball moves faster over the left side than over the right side.

Learn more about the curveball movement here;

https://brainly.com/question/1052138

Answer:

It could be related with the lesson from which this question belongs as far we did not read the lesson

Sorry

The mass of  potassium nitrate (KNO₃) crystals that will be separated is calculated as 6.25 g.

The given parameters:

The mass of KNO₃ at 95 ⁰C is calculated as follows;

[tex]m = \frac{25\ g \times 100\ g}{100\ g} \\\\m = 25 \ g[/tex]

mass of water = 100 g - 25 g = 75 g

The mass of KNO₃ at 55 ⁰C is calculated as follows;

[tex]m = \frac{75 \ g \times 25 \ g}{100 \ g} \\\\m = 18.75 \ g[/tex]

The mass of  potassium nitrate (KNO₃) crystals that will be separated is calculated as;

[tex]m= 25\ g \ - \ 18.75 \ g\\\\m = 6.25 \ g[/tex]

Thus, the mass of  potassium nitrate (KNO₃) crystals that will be separated is calculated as 6.25 g.

Learn more about saturated solution and temperature here: https://brainly.com/question/4529762

Answer:

geothermal energy

Explanation:

the energy is obtained from the heat within the surface of earth

Answer:

heat energy

Explanation:

Answer:

Explanation:

KE = ½mv²

KE = ½(0.30)44²

KE = 290 J                 rounded to 2 s.d.

Answer:

[tex]\huge\boxed{\sf a = 1200\ m/s\²}[/tex]

Explanation:

Given Data:

Initial Velocity = Vi = 40 m/s

Final Velocity = Vf = 80 m/s

Distance = S = 200 m

Required:

Acceleration = a = ?

Formula:

2aS = Vf² - Vi² (THIRD EQUATION OF MOTION)

Solution:

2a (200) = (80)² - (40)²

400a = 6400 - 1600

400a = 4800

Divide 400 to both sides

a = 4800 / 400

a = 1200 m/s²

[tex]\rule[225]{225}{2}[/tex]

Hope this helped!

Answer:

Explanation:

How long does the football need to rise?

4.70/3 = 2.35 s

What height will the football reach?

h = ½(9.81)2.35² = 27.1 m

With what speed does the punter need to kick the football?

vy = g•t = 9.81(2.35) = 23.1 m/s

vx = d/t = 56.0/4.70 = 11.9 m/s

v = √(vx²+vy²) = 26.0 m/s

At what angle (θ), with the horizontal, does the punter need to kick the football?

θ = arctan(vy/vx) = 62.7°

Answer:

Explanation:

Your question makes no sense.

moment of inertia is a property of the disk and its geometry.

The moment of inertia of a uniform solid disk around an axis through its geometric center and perpendicular to its flat ends is

I = ½mR² = ½(3.2)0.45² = 0.324 kg•m²

the applied torque about the same axis would be

τ = FR = 420.4(0.45) = 189.18 N•m

and the angular acceleration about the same axis would be

α = τ/I = 189.18/0.324 = 583.9 rad/s²

Answer:

the answer is force . force is applied as a push or pull

Explanation:

We apply the definition of work by a constant force in the first three parts, but then in the fourth part we add up the answers. The total (net) work is the sum of the amounts of work done by the individual forces, and is the work done by the total (net) force. This identification is not represented by an equation in the chapter text, but is something you know by thinking about it, without relying on an equation in a list.

The definition of work by a constant force is W=FΔrcosθ.

(a) The applied force does work given by

W=FΔrcosθ=(16.0N)(2.20m)cos25.00=31.9J

(b), (c) The normal force and the weight are both at 900 to the displacement in any time interval. Both do 0 work.

(d) ∑W=31.9J+0+0=31.9J

Answer:

1)The position change of almost any manually operated room light switch.

2) Sunlight striking a point on the ground on a partly cloudy and windy day

Explanation:

Answer:

Speed of waves on the rope is 21 m/s

Explanation:

Length of the rope (l) = 5.0 m

Mass of the rope (m) = 0.52 kg

Tension in the rope (T) = 46 N

Formula of speed of waves on the rope:

[tex] \bold{v = \sqrt{\dfrac{T}{\mu}}} [/tex]

[tex] \mu [/tex] = Mass per unit length of the rope (m/l)

By substituting the values in the formula we get:

[tex] \implies \rm v = \sqrt{\dfrac{T}{ \dfrac{m}{l} }} \\ \\ \implies \rm v = \sqrt{\dfrac{Tl}{m}} \\ \\ \implies \rm v = \sqrt{ \dfrac{46 \times 5}{0.52} } \\ \\ \implies \rm v = \sqrt{ \dfrac{230}{0.52} } \\ \\ \implies \rm v = \sqrt{442.3} \\ \\ \implies \rm v = 21 \: m {s}^{ - 1} [/tex]

Speed of waves on the rope (v) = 21 m/s

Answer:

Explanation:

momentum is mass times velocity

p = mv

so take the momentum of the truck in question 17 and divide by the mass of this car

v = p/m = p / 1400

Answer:

7.5m/s

Explanation:

Force= mass × velocity

Energy is conserved, the car and van should have the same overall force.

1500kg × 30m/s= 6000kg × final velocity

Final velocity = 7.5m/s

Hi there!

Impulse = Change in momentum

I = Δp = mΔv = m(vf - vi)

Where:

m = mass of object (kg)

vf = final velocity (m/s)

vi = initial velocity (m/s)

Begin by converting grams to kilograms:

1 kg = 1000g ⇒ 145g = .145kg

Now, plug in the given values. Remember to assign directions since velocity is a vector. Let the initial direction be positive and the opposite be negative.

I = (.145)(-20 - 17) = -5.365 Ns

The magnitude is the absolute value, so:

|-5.365| = 5.365 Ns

Answer:

Explanation:

Conservation of momentum

2500(0) + 1000(30) = (2500 + 1000)v

v = 8.57 m/s

KE = ½(2500 + 1000)8.57² = 128,571.428... = 128 KJ

The kinetic energy of the system after the collision would be 128.5  KJ.

It can be defined as the product of the mass and the speed of the particle, it represents the combined effect of mass and the speed of any particle, and the momentum of any particle is expressed in Kg m/s unit.

As given in the problem Car 1 of mass m1 is waiting at a traffic light.

Car 1 is struck from behind by Car 2 of mass m2. The two cars stick together after the collision. Car 2 was traveling at v2i = 30.0 m/s before the collision.

By using the conservation of the momentum,

2500(0) + 1000(30) = (2500 + 1000)v

v = 8.57 m/s

The final velocity of the system comes out to be  8.57 m/s.

The kinetic energy of the system after the collision,

KE =1/2×(2500 + 1000)×8.57² = 128,571.4

    = 128.5  KJ

Thus, the kinetic energy of the system after the collision would be 128.5  KJ.

To learn more about momentum from here, refer to the link;

brainly.com/question/17662202

#SPJ2

Answer:

Explanation:

constant acceleration???

assume it to be so

average speed is (10 + 30) / 2 = 20 m/s

t = d/v = 60/20 = 3 s

[tex]\text{Given that,}\\\\\text{Initial velocity,} ~v_0 = 0~ \text{m~s}^{-1}\\\\\text{Time, t = 1.3~sec}\\\\\text{Acceleration, a = 9.1 m s}^{-2}\\\\\\\\\text{Velocity,}\\\\v = v_0 +at\\\\\implies v = 0 + 9.1 \times 1.3 = 11.83~~ \text{m~s}^{-1}[/tex]

answer = 6n to the right

Explanation:

2n plus 4n equals 6n

since 6n is more than 5n it goes 6n to the right

]A force called the effort force is applied at one point on the lever in order to move an object, known as the resistance force, located at some other point on the lever.

The way levers work is by multiplying the effort exerted by the user. Specifically, to lift and balance an object, the effort force the user applies multiplied by its distance to the fulcrum must equal the load force multiplied by its distance to the fulcrum. Consequently, the greater the distance between the effort force and the fulcrum, the heavier a load can be lifted with the same effort force.

Answer:

An orbit of a spacecraft from which the spacecraft or another vehicle may be launched on a new trajectory.

Answer:

This is the midline or the medium which is the exact middle of the graphs minimum and maximum points(which are the amplitude)

Answer:

Load

Explanation:

The load in an electric circuit is any device that converts electrical energy into another form of energy.

Hi there!

In this instance, the object's centripetal force is provided by the horizontal component of the tension, so:

Tsinθ = mv²/r

**We use sine because in this situation, the angle is with the vertical**

We can plug in the known values for tension and theta:

60sin(60) = mv²/r

51.96 = mv²/r

The radius is equivalent to the sine of the string in respect to theta:

sin(60) = O/H = r/L

2sin(60) = 1.732 m

Now, solve for the velocity:

51.96 = mv²/r

51.96r / m = v²

51.96(1.732)/.400 = v²

v² = 225

v = 15 m/s