Identify the medium for ocean waves

A ball is dropped out of a window and falls for 8.75 s. What is the ball's final velocity?

Kipish [7]

Answer:

Final velocity of ball is 85.75 m/s

Explanation:

According to the problem, ball is dropped from the window and it experience an acceleration due to Earth's gravity which is denoted by g.

Initially, the ball is at rest, so its initial velocity is zero. The ball takes 8.75 s to fall from the window and hits the ground.

The equation of motion for constant acceleration is :

v = u + at

Here v is final velocity, u is initial velocity, t is time and a is acceleration.

In this case, u is zero and a is equal to g. So, the equation becomes :

v = gt

Substitute 8.75 s for t and 9.8 m/s² for g in the above equation.

v = 9.8 x 8.75

v = 85.75 m/s

3 0

2 years ago

The temperature at a point (x, y) on a flat metal plate is given by T(x, y) = 45/(6 + x2 + y2), where T is measured in °C and x,

Taya2010 [7]

Answer:

Change in x direction is $-1.054^{o}C$

Change in y direction is $-0.35^{o}C$

Explanation:

The temperature is given by we need to find gradient of temperature to obtain the rate of change thus

$T(x,y)=\frac{45}{6+x^{2}+y^{2}}\\\\\therefore \bigtriangledown T(x,y)=\frac{\partial T(x,y)}{\partial x} \widehat{i}+\frac{\partial T(x,y)}{\partial y} \widehat{j}\\\\\frac{\partial T(x,y)}{\partial x}=\frac{-45}{(6+x^{2}+y^{2})^{2}}\times 2x\widehat{i}\\\\\frac{\partial T(x,y)}{\partial y}=\frac{-45}{(6+x^{2}+y^{2})^{2}}\times 2y\widehat{j}\\\\$

Now the rate of change at (3,1) in

1) X direction is given by

$\frac{\partial T(3,1)}{\partial x}=\frac{-45}{(6+3^{2}+1^{2})^{2}}\times 2\times 3\widehat{i}=-1.054\widehat{i}$

2) Y direction is given by

$\frac{\partial T(3,1)}{\partial y}=\frac{-45}{(6+3^{2}+1^{2})^{2}}\times 2\times 1\widehat{j}=-0.35\widehat{j}\\\\$

3 0

2 years ago

If you push a cork into the neck of a bottle filled with air, what happens to the pressure inside the bottle?

Levart [38]

The pressure inside the bottle will build. When you push the cork inside of the bottle the air inside has less space to work with, so it bunches up, making the pressure build up as well.

-Seth

8 0

3 years ago

Sam stands on a 20 m high cliff and throws a 45 g rock with an initial velocity of 5 m/s [forward] to the water below. Use the c

storchak [24]

Answer:

v = 12.52 [m/s]

Explanation:

To solve this problem we must use the energy conservation theorem. Which tells us that potential energy is transformed into kinetic energy or vice versa. This is more clearly as the potential energy decreases the kinetic energy increases.

Ep = Ek

where:

Ep = potential energy [J] (units of joules]

Ek = kinetic energy [J]

Ep = m*g*h

where:

m = mass of the rock = 45 [g] = 0.045 [kg]

g = gravity acceleration = 9.81 [m/s²]

h = elevation = (20 - 12) = 8 [m]

Ek = 0.5*m*v²

where:

v = velocity [m/s]

The reference level of potential energy is taken as the ground level, at this level the potential energy is zero, i.e. all potential energy has been transformed into kinetic energy. In such a way that when the Rock has fallen 12 [m] it is located 8 [m] from the ground level.

m*g*h = 0.5*m*v²

v² = (g*h)/0.5

v = √(9.81*8)/0.5

v = 12.52 [m/s]

5 0

2 years ago

One heater uses 310 W of power when connected by itself to a battery. Another heater uses 180 W of power when connected by itsel

igor_vitrenko [27]

Answer:

55.8W

Explanation:

P= V^2/R

R= V^2/P

For series connection

Req= R1+ R2= V^2/310 + V^2/180

R=V^2/P= V^2/310 + V^2/180

But V^2 will cancel out

P= 1/(1/310 + 1/180)

P= 55.8W

8 0

2 years ago

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