Questions posted in Physics

A baseball is thrown upward from a height of 2 meters with an intial velocity of 10 meters per second . determine its maximum height, using a(t)=-9.8 meters per second as acceleration due to gravity.

The equation to be used for this would be as follows:

h(x) = -9.8x^2 + 10x + 2

We need to find for the axis of symmetry for the time it takes to reach the maximum height and is expressed as:

x = -b/(2a)
x = -10/2(-9.8)
x = 0.51 seconds is the time it takes to reach the max. height

h(x) = -9.8x^2 + 10x + 2
h(x) = -9.8x0.51^2 + 10x0.51 + 2
h(x) = 4.55 m

ANSWERED AT 17/02/2020 - 10:43 AM

QUESTION POSTED AT 17/02/2020 - 10:43 AM

A very thin layer of gold plating was placed on a metal tray that measures 25.22 cm by 13.22cm. The gold plating increased the mass of the plate by 0.0512 g. Calculate the thickness of the plating. The density of gold is 19.31 g/cm ^3

As the volume of gold is 

Volume = mass/ density 

V = 
0.0512g / 19.31gcm^−3

Volume of gold = L. W. T
0.0026 = 52.22 * 13.22 * T
Thickness T = 0.0026 / 690.43

T= 3.7 * 10^-6

ANSWERED AT 17/02/2020 - 10:31 AM

QUESTION POSTED AT 17/02/2020 - 10:31 AM

On the basis of electronegativity, which of these pairs of elements is most likely to form monatomic ions? K and Rb Ba and Ca Na and K Cl and Na

The best and most correct answer among the choices provided by your question is the fourth choice.

Chlorine and sodium are most likely to form monatomic ions.

I hope my answer has come to your help. Thank you for posting your question here in Brainly. We hope to answer more of your questions and inquiries soon. Have a nice day ahead!

ANSWERED AT 16/02/2020 - 06:45 PM

QUESTION POSTED AT 16/02/2020 - 06:45 PM

A 250 mL sample of nitrogen(N2) has a pressure of 745 mm Hg at 30 C.What is the mass of nitrogen?

We assume that nitrogen gas sample here is an ideal gas. So that, we can use the ideal gas equation which is expressed as follows:

PV = nRT

First, we calculate the number of moles from the equation above. Then, use molar mass to calculate mass.

n = PV/RT
n = (745/760) (0.250) / 0.08206 (30+273.15)
n = 0.01 mol 

m = 0.01 ( 28) = 0.28 g

ANSWERED AT 16/02/2020 - 06:42 PM

QUESTION POSTED AT 16/02/2020 - 06:42 PM

I solid iron ball of mass 770kg is used on a building site. The ball is suspended by a rope from a crane. The distance from the point of suspension to the centre of the mass of the ball is 12 m.The ball is pulled back from the vertical and then realeased, it falls through a vertical height of 1.6m and strikes the wall: What is the speed of the ball just before impact? ...?

Based on the given values above, here is the solution which I hope will be helpful to you. 
Triangles, L = 12m, x_0 = 1.6,
we need to find the angle (theta)
sin (theta) = 1.6/12 = 0.1333....
theta = ArcSin(0.1333...) = 0.1337 rad
 hen, this is the height that the mass vertically raises in it's arc
y_2 = L-L*cos(theta) = 0.107 m
use y_2 in a kinematic swing... v=√2gy^2 = 1.45m/s
The speed would be 1.45m/s. Hope this answer helps.

ANSWERED AT 16/02/2020 - 06:38 PM

QUESTION POSTED AT 16/02/2020 - 06:38 PM

How and why does the distance between 2 electrodes affect the rate of electrolysis? ...?

 Nothing, in terms of the chemistry. 

The distance between the electrodes affects the electrical resistance very slightly. Increasing the distance increases the resistance and reduces the current slightly, which reduces slightly the amount of product. 

For most practical applications, for electrolysis done in a beaker, varying the distance between the electrodes will make little difference. 

Increasing the concentration of the electrolyte will increase the current flow because there are more charged particles to carry charge, and increase the product yield.

ANSWERED AT 16/02/2020 - 06:36 PM

QUESTION POSTED AT 16/02/2020 - 06:36 PM

Help with number 4 please.

 because it will get smaller and smaller until it dissapears so therefore it decreases

ANSWERED AT 16/02/2020 - 06:13 PM

QUESTION POSTED AT 16/02/2020 - 06:13 PM

A sign has a mass of 1050 kg, a height h = 1 m, and a width W = 4 m. It is held by a light rod of length 5 m that is perpendicular to a rough wall. A guy wire at 23° to the horizontal holds the sign to the wall. Note that the distance from the left edge of the sign to the wall is 1 m. Suppose we rely upon friction between the wall and the rod to hold up the sign (there is no hinge attaching the rod to the wall). What is the smallest value of the coefficient of friction µ such that the sign will remain in place? ...?

the reason I use the moments is for a problem to be in static equilibrium the moments about any point is zero the reason I take the moments about where the rod touches the wall is the unknown horizontal force and force of friction are produce zero moments at that point the only contributing forces are the tension in the guy wire and the weight acting down the weight can be considered a point acting at a distance 3 meters from the wall along the rod since the sigh is attached to the rod why i used y' is to reduce variables; the moment is the same y' * T = y T(vertical); just wanted to find total T in one step sum M about O = 0 = W*3m - T(y') solve for T then use Net Force X = 0 therefore R(horizontal) = T(horizontal) use Net Force Y = R(vertical) + T(vertical) - W = 0 the reaction horizontal is where the rod meets the wall and is the normal force or from a materials point of veiw where the rod is being compressed into the wall the reaction vertical is the force of friction along the end of the rod on the wall you need on final formula force of friction = µ * normal force( which is R(horizontal))

ANSWERED AT 16/02/2020 - 05:34 PM

QUESTION POSTED AT 16/02/2020 - 05:34 PM

-Which of the following wires will have the least resistance? A. A long thin wire B. A short thin wire C. A short thick wire D. A long thick wire ...?


Option (C)


The obstruction offered by the conductor in the path of flow of electrons is called the resistance of the conductor.

The reistance of the conductor is directly proportional to the length of the conductor and inversely proportional to the area of crossection of the conductor.

To minimize the resistance we need a wire of short length and more crossection area.

So, wire should be short and thick.

ANSWERED AT 16/02/2020 - 05:34 PM

QUESTION POSTED AT 16/02/2020 - 05:34 PM

How are atoms in a magnet arranged? A. according to their magnetic poles B. according to their magnetic force C. according to their magnetic properties D. according to their magnetic areas

Atoms in a magnet are arranged according to their magnetic poles. Their north and south poles determine how the atoms in the magnet are arranged.

ANSWERED AT 16/02/2020 - 05:32 PM

QUESTION POSTED AT 16/02/2020 - 05:32 PM

How can we reduce the ripple factor of a bridge recitifier from 0.48 to 0.1 approximately ?

U can try to use capacitor , the value of capacitor depends on circuit

ripple factors signifies the ac components, by def its ratio of rms value of ac component to value of dc component
so in order to reduce use of a capacitor which denies the sudden changes in voltage, which is the charracteristic of Ac signals

hope this helps

ANSWERED AT 16/02/2020 - 05:24 PM

QUESTION POSTED AT 16/02/2020 - 05:24 PM

Light energy is a form of

Electromagnetic spectrum

ANSWERED AT 16/02/2020 - 04:52 PM

QUESTION POSTED AT 16/02/2020 - 04:52 PM

A metal bar 70cm long and 4.00 kg in mass supported on two knief -edge placed 10 cm from each end. a 6.00 kg weight is suspended at 30 cm from one end . find the reaction at the knife-edge ?

The reactions at the knife-edges supporting the metal bar are \boxed{56\,{\text{N}}\,{\text{\& }}\,{\text{44}}\,{\text{N}}} .

Further Explanation:

Since the metal bar is balanced at the knife edges. The net torque about the two knife edges will be zero.

Consider the reaction force at the first knife edge is {F_1} and at the second knife edge is {F_2} as shown in the figure below.

The weight of the metal ball is acting at the center of the bar i.e. 35{\text{ cm}} from the end of the bar. The weight of the metal bar is:

\begin{aligned}W&= mg\\&=4\times10\\&= 40\,{\text{N}}\\\end{aligned}

The reaction of the 6\,{\text{kg}} mass is:

\begin{aligned}W'&=m'g\\&=6\times 10\\&= 60\,{\text{N}}\\\end{aligned}

The net torque about the point A can be expressed as:

\begin{aligned}{F_2}\times 0.5 &=\left({60 \times 0.3} \right)+\left({40 \times 0.25} \right)\\{F_2}&=\frac{{18 + 10}}{2}\\&= 56\\\end{aligned}

The net torque about the point   can be expressed as:

\begin{aligned}{F_1}\times 0.5 &= \left({60 \times 0.2}\right) + \left({40 \times 0.25} \right)\\{F_1}&=\frac{{12 + 10}}{2}\\&=44\\\end{aligned}

Thus, the reactions at the knife-edges supporting the metal bar are \boxed{56\,{\text{N}}\,{\text{\& }}\,{\text{44}}\,{\text{N}}}.

1. A horizontal, 2.00 m long, 3.00 kg uniform beam that lies along the east-west direction is acted on by two forces

2. Two arrows are fired simultaneously with the same speed of 30.0 m/s. Each arrow has a mass of 0.100 kg

3. The amount of kinetic energy an object has depends on its https://brainly.cLearn More: om/question/137098

Answer Details:

Grade: High School

Subject: Physics

Chapter: Torque and Moment

Keywords:  Metal bar, 70cm long, supported, two knife-edge, 10cm from each end, weight is suspended, reaction at, net torque, center of metal bar.

ANSWERED AT 16/02/2020 - 04:21 PM

QUESTION POSTED AT 16/02/2020 - 04:21 PM

A particular type of automobile storage battery is characterized as "207 - Ampere - hour, 9.4 V." What total energy can the battery deliver? Answer in units of J.

Electric Energy = Current x Voltage x time = 207 x 9.4 = 1,945.8 J

ANSWERED AT 16/02/2020 - 04:11 PM

QUESTION POSTED AT 16/02/2020 - 04:11 PM

What is ham, I'm totally serious?

Ham is a dead sliced pig that you put on sandwiches

ANSWERED AT 16/02/2020 - 03:47 PM

QUESTION POSTED AT 16/02/2020 - 03:47 PM

A change in ________ results in ________. a. time, acceleration c. acceleration, velocity b. velocity, acceleration d. none of the above

I think it's C. I may be wrong, tho

ANSWERED AT 16/02/2020 - 03:43 PM

QUESTION POSTED AT 16/02/2020 - 03:43 PM

At what volume of added base is the ph calculated by working an equilibrium problem based on the initial concentration and ka of the weak acid?

In an acid-base neutralization reaction, the equilibrium reaction would be between a weak acid and its conjugate strong base. So, this must be the basis of the volume of added base. Its product would most likely be a basic salt.

ANSWERED AT 16/02/2020 - 03:32 PM

QUESTION POSTED AT 16/02/2020 - 03:32 PM

I need help with a science project about the crust of the earth!!

What's the question?

ANSWERED AT 16/02/2020 - 06:38 AM

QUESTION POSTED AT 16/02/2020 - 06:38 AM

Which environmental hazard is directly related to nuclear power production stripping warming C.radiation leakage D.soil erosion


Radiation leakage


Radiation leakage mans radiations scattered in all possible direction through X-ray tube. Due to radiation leakage useful radiations as well as harmful radiations are scattered in all directions. Due to radiation leakage many harmful effect can be observed in the environment. This is hazardous process many times.

Thus radiation leakage through the nuclear power production is hazardous.

ANSWERED AT 16/02/2020 - 04:49 AM

QUESTION POSTED AT 16/02/2020 - 04:49 AM

When a shotgun fires, a sequence of events takes places? After the hunter pulls the trigger, what is the next event in the sequence

The shooting pin attacks the primer. First, sparks ignite the gun powder, powder burns into gas, gas is fired out of the barrel.

Further Explanation

The sequence of events occurs when a shotgun is fired, where one leads the other. When the hunter pulls the trigger, first the firing pin attacks the primer. Then, a spark occurred which ignited gunpowder. When the gunpowder burns, it turns to gas and expands which eventually pushes the shot through the barrel. This is how a shotgun is fired.

The first handguns were basically miniature cannons; You loaded some gunpowder, a steel ball and lit the fuse. In the end, this technology provides a way to trigger activated weapons, such as flintlock shotguns and lighted shotguns. Flintlock percussion gunpowder by producing a small spark, while the gunpowder axis is used mercuric chided, your explosive compounds can ignite with sharp blows. To load the gun's percussion cap, you pour gunpowder into the breach, stuff the projectile on top of it, and place a mercuric chide cap over the small nipples. To fire a gun, you tilt the hammer all the way back and pull the gun's trigger. Released a hammer trigger, which swings forward to an explosive cap. The lid was ignited, shooting a small fire into a tube into gunpowder. The gunpowder exploded, launching bullets out of the barrel.

Learn more

How rifles work


Grade:  High School

Subject:  Physics

keywords: Gun, gunpowder.

ANSWERED AT 16/02/2020 - 02:20 AM

QUESTION POSTED AT 16/02/2020 - 02:20 AM

Two 4.0 kg masses are 1.0 m apart on a frictionless table. Each has 1.0 μC of charge.What is the magnitude of the electric force on one of the masses?

Coulomb's law:

  Force = (8.99×10⁹ N m² / C²) · (charge₁) · (charge₂) / distance²

            = (
8.99×10⁹ N m² / C²) (1 x 10⁻⁶ C) (1 x 10⁻⁶ C)  / (1.0 m)²

            = (8.99×10⁹ x 1×10⁻¹² / 1.0)  N

            =      8.99×10⁻³  N

            =        0.00899 N repelling.

Notice that there's a lot of information in the question that you don't need.
It's only there to distract you, confuse you, and see whether you know
what to ignore.

-- '4.0 kg masses';  don't need it. 
   Mass has no effect on the electric force between them.

-- 'frictionless table';  don't need it.
   Friction has no effect on the force between them,
only on how they move in response to the force.

ANSWERED AT 16/02/2020 - 02:15 AM

QUESTION POSTED AT 16/02/2020 - 02:15 AM

Sunlight travels 150,000,000 km from the sun to the earth because of?

The Speed of Light.
Photons emitted from the surface of the sun to travel across the vacuum of space to reach out eyes

ANSWERED AT 16/02/2020 - 02:14 AM

QUESTION POSTED AT 16/02/2020 - 02:14 AM

A rescue line is to be thrown horizontally from the bridge of a cruise ship at 40.0 m above sea level to a life boat 50.0 m away with what horizontal speed should the rescue line be thrown?

There is a 40m drop from the bridge, so we can work out the time of the vertical component first (how long it will take to reach the water) 

do this by using a SUVAT equation s=ut+0.5at^2
this rearranges to t= sqrt(2s/a)
- note that u has been removed since there is no initial velocity.
sqrt((2*40)/9.81)= 2.86 seconds 

this means that the horizontal component of 50m has so be covered in 2.86s 
and speed = distance/ time 


the line has to be thrown at 17.48ms^-1 or more to reach the life boat. 

ANSWERED AT 16/02/2020 - 02:03 AM

QUESTION POSTED AT 16/02/2020 - 02:03 AM

A sled going down a hill covered in snow eventually comes to a stop. Explain why this happens in terms of energy. Use the terms potential energy, kinetic energy, and me please.


Initially the body possess potential energy and then kinetic energy as the body slides down the hill. The sled comes to a halt due to the force of friction that exists between the tyre of the sled and the snow.


Before the sled start coming down the hill, it was initially at a state of rest (not moving). At that point of rest, the velocity of the body is zero and the body possess potential energy because potential energy is the energy possessed by a body by virtue of its position. As the body slides down the hill, it gains energy to move(its velocity increases) and invariably possessing kinetic energy which is the energy possessed by a body by virtue of its motion.

The sled then eventually comes to a stop due to the force of friction that exist been the tyre of the sled and the snow(which are both rough surfaces) because friction tends to occur between two "rough" surfaces in contact thereby bringing the body to a halt(rest).

ANSWERED AT 16/02/2020 - 01:59 AM

QUESTION POSTED AT 16/02/2020 - 01:59 AM

If a 100-N net force acts on a 50-kg car, what will the acceleration of the car be?

Newton's 2nd law of motion: 

                             Force = (mass) x (acceleration)

Divide each side by (mass):     

                             Acceleration = (force) / (mass)

                                               =  (100 N) / (50 kg)

                                               =  2 m/s²  

ANSWERED AT 16/02/2020 - 12:41 AM

QUESTION POSTED AT 16/02/2020 - 12:41 AM

A car drives for 30 km with a speed of 30m/s. How much time does it take the car to travel this distance?

                   Time  =  (distance)  /  (speed)

                           =  (30 km)  /  (30 m/s)

                           =  (30,000 m)  /  (30 m/s)

                           =  (30,000 / 30)  sec

                           =      1,000 seconds

                           =      16 minutes  40 seconds  

ANSWERED AT 16/02/2020 - 12:38 AM

QUESTION POSTED AT 16/02/2020 - 12:38 AM

What is the mass of a cannonball if a force of 2,500 N gives the cannonball an acceleration of 200m/s2?

Newton's 2nd law of motion:

                         Force = (mass) x (acceleration)

Divide each side
by 'acceleration':      Mass  =  (force) / (acceleration)

                                       =  (2,500 N)  /  (200 m/s²)

                                       =    12.5 kg

ANSWERED AT 16/02/2020 - 12:36 AM

QUESTION POSTED AT 16/02/2020 - 12:36 AM