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3 years ago

What is the change in internal energy if 60 J of heat are released from a

Physics

1 answer:

lana [24]3 years ago

7 0

Answer:

60 J of heat are released from the system: Q=-60 J

20 J of work is done on the system: W=-20 J

∆U=Q-W

∆U=-60-(-20)

∆U=-40 J

Explanation:

If the heat is released from the system, Q should be negative.

If the heat is gained by the system, Q should be positive.

If the work is done on the system, W should be negative.

If the work is done by the system, W should be positive.

You might be interested in

Light enters water from air at an angle of 25° with the normal, Θ1. If water has an index of refraction of 1.33, determine Θ2.

vladimir1956 [14]

By Snell's law:

η = sini / sinr. i = 25, η = 1.33

1.33 = sin25° / sinr

sinr = sin25° / 1.33 = 0.4226/1.33 = 0.3177 Use a calculator.

r = sin⁻¹(0.3177)

r ≈ 18.52°

Option A.

God's grace.

6 0

3 years ago

A solid block of mass m2 = 1.14 kg, at rest on a horizontal frictionless surface, is connected to a relaxed spring (with spring

borishaifa [10]

Answer:

v = 1 m/s

Explanation:

from the principle of conservation of momentum, we have following relation

initial momentum = final momentum

$m_{1}v_{1}+m_{2}v_{2} = (m_{1}+m_{2})v^{2}$

where

m1 = 1.14 kg

v1 = 2.0 m/s

m2 = 1.14 kg

v2 = 0 m/s

putting all value in the above equation

$1.14 *2.0+ 0 =(1.14+1.14)v^{2}$

$v =\frac{1.14*2.0}{1.14+1.14}$

v = 1 m/s

4 0

3 years ago

If you throw a ball down ward then acceleration immeditely after leaving your hand is

bezimeni [28]

Answer:

9.8m/s²

Explanation:

The acceleration of the ball thrown after leaving my hand is 9.8m/s². This will be the acceleration due to gravity on the body.

Acceleration due to gravity is caused by the pull of the earth on a massive object.
The value of this acceleration is 9.8m/s².
As the ball nears the surface, it comes near zero.

7 0

2 years ago

A 1,000 kg car is travelling at 6.5 m/s to the North. A 3,500 kg truck is travelling South at the same velocity. What is the tot

Molodets [167]

Answer:

16250 kgm/s due south

Explanation:

Applying,

M = mv................. Equation 1

Where M = momentum, m = mass, v = velocity.

From the car,

Given: m = 1000 kg, v = 6.5 m/s

Substitute these values into equation 1

M = 1000(6.5)

M = 6500 kgm/s

For the truck,

Given: m = 3500 kg, v = 6.5 m/s

Substitute these values into equation 1

M' = 3500(6.5)

M' = 22750 kgm/s.

Assuming South to be negative direction,

From the question,

Total momentum of the two vehicles = (6500-22750)

Total momentum of the two vehicles = -16250 kgm/s

Hence the total momentum of the two vehicles is 16250 kgm/s due south

3 0

2 years ago

4. A family leaves from New York City and is flying to Los Angles which is 2800mi away. It takes

Blizzard [7]

The average speed of the whole travel is equal to <u>400 mph</u>.

Why?

From the statement, we know that whole travel is divided into three parts. For the first part (traveling from New York to Chicago), we have that it was 3.25 hours and the covered distance was half of the total distance (1400mi). For the second part, we have that it was 1 hour (layover time), and the covered no distance. For the third part (traveling from Chicago to Los Angeles), we have that it was 2.75 hours, and it took the other half of the total distance (1400mi).

We can calculate the average speed of the whol travel using the following formula:

$AverageSpeed=\frac{distance_{1}+distance_{2}+distance_{3}}{time_{1}+time{2}+time_{3}}$

Now, substituting and calculating, we have:

$AverageSpeed=\frac{1400mi+0mi+1400mi}{3.25h+1h+2.75h}$

$AverageSpeed=\frac{2800mi}{7h}=400mph$

Hence, we have the average speed of the whole travel is equal to 400 mph.

Have a nice day!

7 0

3 years ago