A train travels 80 kilometers in 2 hours, and then 79 kilometers in 4 hours. What is its average speed?

Urgent!

Masja [62]

mass of iron block given as

$m_1 = 1.90 kg$

density of iron block is

$\rho = 7860 kg/m^3$

now the volume of the iron piece is given as

$V = \frac{m}{\rho}$

$V = \frac{1.90}{7860} = 2.42* 10^{-4} m^3$

Now when this iron block is complete submerged in oil inside the beaker the buoyancy force on the iron block will be given as

$F_b = \rho_L V g$

here we know that

$\rho_L$ = density of liquid = 916 kg/m^3

$F_b = 916* 2.42 * 10^{-4} * 9.8$

$F_b = 2.17 N$

Now for the reading of spring balance we can say the spring force and buoyancy force on the block will counter balance the weight of the block at equilibrium

$F_s + F_b = mg$

$F_s + 2.17 = 1.90* 9.8$

$F_s = 16.45 N$

So reading of spring balance will be 16.45 N

Now for other scale which will read the normal force of the surface we can write that normal force on the container will balance weight of liquid + container and buoyancy force on block

$F_n = F_g + F_b$

$F_n = (1 + 2.50)*9.8 + 2.17$

$F_n = 34.3 + 2.17 = 36.47 N$

So the other scale will read 36.47 N

3 0

3 years ago

umka2103 [35]

You can hear a difference between these two sounds. That is because their pitch isdifferent. Pitch depends on the frequency of a sound wave. ... High sounds have highfrequencies and low sounds have lowfrequencies.

4 0

4 years ago

Describe how the coriolis effect acts differently based on location on earth

sammy [17]

Explanation:

The Coriolis effect happens when an entity is perceived from a moving reference frame going in a straight path. The changing reference frame makes the object appear as if it were moving along a curved road.

Circulation is counter-clockwise in the northern hemisphere. Circulation is clockwise in the southern hemisphere, and it is the equator, it is straight down without circulation.

6 0

3 years ago

a 700k/g race car slowed down from 30m/s to 15m/s what is the impulse and what was the average force applied by the brakes

posledela

So impulse is a change in momentum.

Mass*(final velocity - initial velocity)

I dont think you will be able to find the average force with the given info because you need to know the time it takes for the car to slow down.

5 0

3 years ago

A circle has an initial radius of 50ft when the radius begins decreasing at a rate of 2ft/s. what is the rate of change of the a

valkas [14]

The area of the circle with radius r is
A = πr²

The rate of change of area with respect to time is
$\frac{dA}{dt} = \frac{dA}{dr} . \frac{dr}{dt} =2 \pi r. \frac{dr}{dt}$

The rate of change of the radius is given as
$\frac{dr}{dt} =-2 \, \frac{ft}{s}$
Therefore
$\frac{dA}{dt} =-4 \pi r \, \frac{ft^{2}}{s}$

When r = 10 ft, obtain
$\frac{dA}{dt}|_{r=10 \, ft} = -40 \pi \, \frac{ft^{2}}{s}$

Answer: - 40π ft²/s (or - 127.5 ft²/s)

7 0

4 years ago