How electricity has changed what we do for entertainment?

A car travels 50 kilometers in 30 minutes. Which<br> about the motion of the car are true?

irga5000 [103]

Answer:

1500

Explanation:

is that all the question?

6 0

9 months ago

A tissue sample at 275 K is submerged in 2 kg of liquid nitrogen at 70 K for cryopreservation. The final temperature of the nitr

kirill115 [55]

Answer:

The heat capacity of a sample is 37.7 J/K.

Explanation:

Given that,

Submerged temperature of tissue sample = 275 K

Mass of liquid nitrogen= 2 kg

Temperature = 70 K

Final temperature = 75 K

We need to calculate the heat

Using formula of heat

$Q=mc(T_{f}-T_{i})$

Put the value into the formula

$Q=2\times1.039\times10^{3}\times(75-70)$

$Q=10390\ J$

We need to calculate the heat capacity of a sample

Using formula of heat capacity

$\Delta S=\dfrac{Q}{T}$

Put the value into the formula

$\Delta S=\dfrac{10390}{275}$

$\Delta S=37.7\ J/K$

Hence, The heat capacity of a sample is 37.7 J/K.

7 0

2 years ago

Read 2 more answers

You drop a ball from a window located on an upper floor of a building. It strikes the ground with speed v. You now repeat the dr

bulgar [2K]

Answer:

y = y₀ (1 - ½ g y₀ / v²)

Explanation:

This is a free fall problem. Let's start with the ball that is released from the window, with initial velocity vo = 0 and a height of the window i

y = y₀ + v₀ t - ½ g t²

y = y₀ - ½ g t²

for the ball thrown from the ground with initial velocity v₀₂ = v

y₂ = y₀₂ + v₀₂ t - ½ g t²

in this case y₀ = 0

y₂2 = v t - ½ g t²

at the point where the two balls meet, they have the same height

y = y₂

y₀ - ½ g t² = vt - ½ g t²

y₀i = v t

t = y₀ / v

since we have the time it takes to reach the point, we can substitute in either of the two equations to find the height

y = y₀ - ½ g t²

y = y₀ - ½ g (y₀ / v)²

y = y₀ - ½ g y₀² / v²

y = y₀ (1 - ½ g y₀ / v²)

with this expression we can find the meeting point of the two balls

6 0

2 years ago

Given vectors D (3.00 m, 315 degrees wrt x-axis) and E (4.50 m, 53.0 degrees wrt x-axis), find the resultant R= D + E. (a) Write

fomenos

Answer:

(a) $\vec{R}= 4.83\ m\ \hat{i}+1.47\ m\ \hat{j}$

(b) (5.05 m, 16.93 degrees wrt x-axis)

Explanation:

Given:

$\vec{D}$ = (3.00 m, 315 degrees wrt x-axis)
$\vec{E}$ = (4.50 m, 53.0 degrees wrt x-axis)

Let us first fond out vector D and E in their rectangular form.

$\vec{D} = (3\cos 315^\circ\ \hat{i}+3\sin 315^\circ\ \hat{j})\ m\\\Rightarrow \vec{D} = (2.12\ \hat{i}-2.12\ \hat{j})\ m\\$

Similarly,

$\vec{E} = (4.5\cos 53^\circ\ \hat{i}+4.5\sin 53^\circ\ \hat{j})\ m\\\Rightarrow \vec{D} = (2.71\ \hat{i}+3.59\ \hat{j})\ m\\\because \vec{R}=\vec{D}+\vec{E}\\\therefore \vec{R} = (2.12\ \hat{i}-2.12\ \hat{j})\ m+(2.71\ \hat{i}+3.59\ \hat{j})\ m\\\Rightarrow \vec{R} = (4.83\ \hat{i}+1.47\ \hat{j})\ m$

Part (a):

We can write the resultant vector R as below:

$\vec{R} = (4.83\ \hat{i}+1.47\ \hat{j})\ m$

Part (b):

$Magnitude\ of\ resultant = \sqrt{4.83^2+1.47^2}\ m = 5.05\ m\\\textrm{Direction in angle with the x-axis} = \theta = \tan^{-1}(\dfrac{1.47}{4.83})= 16.93^\circ$

Since both the components of the resultant lie on the positive x and y axes. So, the resultant makes an acute angle with the positive x-axis.

So, R = (5.05 m, 16.93 degrees wrt x-axis)

3 0

2 years ago

What different forms of energy are present when an egg crashes into the egg catcher?

Sonbull [250]

Answer:

An egg raised above the ground has potential energy due to the force of gravity. When dropped, the egg's potential energy is converted into the kinetic energy of motion. :)

Explanation:

7 0

2 years ago