I need help with number 6

ra1l [238]

C should be the answer

8 0

3 years ago

A 4.6-kg block of ice originally at 263 K is placed in thermal contact with a 15.7-kg block of silver (cAg = 233 J/kg-K) which i

Viktor [21]

Answer:

temperature at 326.44 K system achieve equilibrium

Explanation:

given data

mass of block of ice = 4.6 kg

temperature = 263 K

thermal contact = 15.7-kg

specific heat of silver cAg = 233 J/kg-K

initially temperature = 1052 K

to find out

what temperature will the system achieve equilibrium

solution

first we consider final temperature of the system is T

we know that specific heat of water (C w) = 4186 J(kg K)

and

specific heat of ice ( C i ) = 2030 J/(kg K)

and

latent heat of fusion of ice ( Lf ) = 3.33 × $10^{5}$ J/kg

and we know that system is insulated

so heat lost by silver = heat generated by ice .................1

so we can say

mass of silver × specific heat of silver × ( initial temp - final temp ) = mass of ice × specific heat of ice × ( ice temp ) + mass of ice × latent heat of fusion of ice + mass of ice × specific heat of water × (final temperature )

put here value we get

mass of silver × specific heat of silver × ( initial temp - final temp ) = mass of ice × specific heat of ice × ( ice temp ) + mass of ice × latent heat of fusion of ice + mass of ice × specific heat of water × (final temperature )

15.7 × 233 × ( 1052 - T ) = 4.6 × 2030 × 10 + 4.6 × 3.33 × $10^{5}$ + 4.6 × 4286 × ( T - 273 )

solve we get

T = 326.44 K

so temperature at 326.44 K system achieve equilibrium

7 0

3 years ago

A ball is thrown vertically upwards with an initial velocity of 20.00 m/s. Neglecting air resistance, how long is the ball in th

algol [13]

Answer:

1) The greatest height attained by the ball equals 20.387 meters.

2) The time it takes for the ball to reach 15 meters approximately equals 1 second.

Explanation:

The greatest height will be attained when the ball stop's in the air and starts falling back to the earth.

thus using third equation of kinematics we obtain the height attained as

$v^2=u^2+2as$

where

'v' is the final speed of the ball

'u' is the initial speed of the ball

'a' is the acceleration that the ball is under which in this case equals 9.81 $m/s^{2}$

's' is the distance it covers

Thus for maximum height applying the values in the equation we get

$0=20^{2}-2\times 9.81\times h\\\\\therefore h=\frac{20^{2}}{2\times 9.81}=20.387meters$

Using the same equation we can find the speed of the ball when it reaches 15 meters of height as

$v^2=20^{2}-2\times 9.81\times 15\\\\v^{2}=105.7\\\\\therefore v=10.28m/s$

the time it takes to reduce the velocity to this value can be found by first equation of kinematics as

$v=u+at\\\\t=\frac{v-u}{a}\\\\t=\frac{10.28-20}{-9.81}=0.991seconds\approx 1second$

4 0

3 years ago

3. When a person is outside of the system and they add energy to the

NISA [10]

Answer:

We show added energy to a system as +Q or -W

Explanation:

The first law of thermodynamics states that, in an isolated system, energy can neither be created nor be destroyed;

Energy is added to the internal energy of a system as either work energy or heat energy as follows;

ΔU = Q - W

Therefore, when energy is added as heat energy to a system, we show the energy as positive Q (+Q), when energy is added to the system in the form of work, we show the energy as minus W (-W).

5 0

3 years ago

What is the definition of motivation?

elixir [45]

Motivation is an encouragement to do or achieve something

5 0

3 years ago