A thin film of oil rests on an inclined plane

In the 19th century James Joule, an English scientist, was the first to recognize the mechanical equivalent of heat as a specifi

Dmitry [639]

Answer:

D) wood rubbed against a rough surface feels hot

Explanation:

The heat is transferred from one form of energy (friction of the wood being rubbed against the surface) to another (heat energy).

6 0

4 years ago

Read 2 more answers

A truck traveling at a constant speed of 28 m/s passes a more slowly moving car. The instant the truck passes the car, the car b

choli [55]

Answer:

the velocity of car when it passes the truck is u = 16.33 m/s

Explanation:

given,

constant speed of truck = 28 m/s

acceleration of car = 1.2 m/s²

passes the truck in 545 m

speed of the car when it just pass the truck = ?

time taken by the truck to travel 545 m

time = $\dfrac{distance}{speed}$

time = $\dfrac{545}{28}$

time =19.46 s

velocity of the car when it crosses the truck

$S = ut + \dfrac{1}{2}at^2$

$545= u\times 19.46 + \dfrac{1}{2} \times 1.2 \times 19.46^2$

u = 16.33 m/s

the velocity of car when it passes the truck is u = 16.33 m/s

5 0

3 years ago

A uniform disk with a mass of 5.0 kg and diameter 30 cm rotates on a frictionless fixed axis through its center and perpendicula

igomit [66]

Answer:

Angular acceleration of the disk will be $\alpha =10.714rad/sec^2$

Explanation:

We have given mass of the disk m = 5 kg

Diameter of the disk d = 30 cm = 0.3 m

So radius $r=\frac{d}{2}=\frac{0.3}{2}=0.15m$

Moment of inertia of disk is given by $I=\frac{1}{2}mr^2=\frac{1}{2}\times 5\times 0.15^2=0.056kgm^2$

Force is given by F=4 N

Torque is given as $\tau =Fr=4\times 0.15=0.6N-m$

We also know that torque is given by $\tau =I\alpha$

$0.6=0.056\times \alpha$

$\alpha =10.714rad/sec^2$

5 0

3 years ago

Explain how atoms of elements form molecules, compounds and mixtures.

katrin2010 [14]

An element is composed of millions of atoms and a compound is composed of molecules. When an atom reacts with another atom, a molecule is formed.

For example, if sodium reacts with chloride, it forms sodium chloride (Common salt). Here, sodium and chloride are elements and sodium chloride is a molecule. In this way, millions of atoms of sodium reacts with chloride and forms common salt.

Again, when the common salt is mixed with other compounds such as water, it forms a mixture.

6 0

3 years ago

What property do protons can electrons have that neutrons do not ?

Vesna [10]

Answer:

Protons and electrons are charged particles. Neutrons have no charge.

4 0

3 years ago