Ben walks 500 meters from his house to the corner store. He then walks back toward his house but stops to talk to a

How much energy is needed to heat and melt 3.0 kg of copper initially at 83°C?

Ne4ueva [31]

As we know that in order to melt the copper we need to take the temperature of copper to its melting point

So here heat required to raise the temperature of copper is given as

$Q = ms\Delta T$

We know that

melting temperature of copper = 1085 degree C

Specific heat capacity of copper = 385 J/kg C

now we have

$Q = 3(385)(1085 - 83)$

$Q = 1157310 J$

$Q = 1157.3 kJ$

now in order to melt the copper we know the heat required is

$Q = mL$

here we know that

L = 205 kJ/kg

now from above formula

$Q = 3(205) kJ$

$Q = 615 kJ$

now total heat required will be

$Q = 1157.3 kJ + 615 kJ$

$Q = 1772.3 kJ$

As we know that

$1 Cal = 4.18 kJ$

now we have

$Q = \frac{1772.3}{4.18} = 430 KCal$

6 0

2 years ago

A carpenter is driving a 15.0-g steel nail into a board. His 1.00-kg hammer is moving at 8.50 m/s when it strikes the nail. Half

bekas [8.4K]

Answer: The increase in temperature of the nail after the three blows is 8.0636 Kelvins. The correct option is (d).

Explanation:

Kinetic energy of the hammer ,K.E.=

$\frac{1}{2}mv^2=\frac{1}{2}1.00 kg\times (8.50 m/s)^2=36.125 J$

Half of the kinetic energy of the hammer is transformed into heat in the nail.

Energy transferred to the nail in one blow =

$\frac{1}{2}K.E.=\frac{1}{2}\times 36.125 J=18.0625 J$

Total energy transferred after 3 blows,Q = $3\times 18.0625 J=54.1875 J$

Mass of the nail = 15 g = 0.015 kg

Change in temperature = $\Delta T$

Specif heat of the steel = c = 448 J/kg K

$Q=mc\Delta T$

$54.1875 J=0.015 kg\times 448 J/kg K\times \Delta T$

$\Delta T=8.0636 K\approx 8.1 K$

The increase in temperature of the nail after the three blows is 8.1 Kelvins.Hence, correct option is (d).

4 0

2 years ago

If you increase the force on an item without changing the mass you increase acceleration? true or false?

rusak2 [61]

(F)(M)=A
Force times Mass equals Acceleration.
The answer is TRUE.
If the mass increases the number on the left side of the equation increases, thus increasing the right side as well.

5 0

3 years ago

What is the volume of a storage tank which will hold 3200kg of petrol?

otez555 [7]

Answer:

The volume of 3200 kg of petrol is 4 m^3.

4 0

2 years ago

NewtonsXmeters / time is a unit of which of the following:

GuDViN [60]

Answer:

energy I think I'm not sure of the answer.

7 0

2 years ago