Any change that alters a substance without changing it into another substance is an change

If two objects are the same size but one object is 3 times hotter than the other object, the hotter object emits If two objects

Illusion [34]

Answer:

81 times the first body

Explanation:

Let the temperature of the first object is T.

The temperature of the second object is 3T.

According to the Stefan's law, the energy radiated per unit area per unit time is given by

$E \alpha T^{4}$

So, for the first body

$E_{1} \alpha T^{4}$ .... (1)

for the second body

$E_{2} \alpha (3T)^{4}$ ..... (2)

By equation (1) and (2),

E2 = 81 times E1

So, the second body gives 81 times more energy per unit area per unit time

8 0

3 years ago

A lamp is connected to the power supply.

Vika [28.1K]

Answer:

There are 45 turns in the secondary coil.

Explanation:

Given that,

Input potential of the lamp, $V_{in}=5\ V$

The output potential of the lamp, $V_{out}=1.5\ V$

Number of turns in primary coil, $N_P=150$

We need to find the number of turns needed on the secondary coil. We know that the ratio for a transformer is as follows :

$\dfrac{V_{out}}{V_{in}}=\dfrac{N_s}{N_P}\\\\N_s=\dfrac{V_{out}N_P}{V_{in}}\\\\N_s=\dfrac{1.5\times 150}{5}\\\\N_s=45\$

So, there are 45 turns in the secondary coil.

5 0

3 years ago

You are riding a bicycle home from school. You average 5 meters per second and you are headed south.

olchik [2.2K]

Answer:

(OD) Velocity

Explanation:

Here, the rider is moving with a steady speed (5 m/s) towards south. In this example, we have magnitude as well as direction. Since velocity is a vector quantity, thus we can determine the velocity of the rider.

5 0

3 years ago

A 400-n block is dragged along a horizontal surface by an applied force as shown. the coefficient of kinetic friction is uk = 0.

gulaghasi [49]

The block moves with constant velocity: for Newton's second law, this means that the resultant of the forces acting on the block is zero, because the acceleration is zero.

We are only concerned about the horizontal direction, and there are only two forces acting along this direction: the force F pushing the block and the frictional force $F_f$ acting against the motion. Since their resultant must be zero, we have:
$F-F_f = 0$
The frictional force is
$F_f = \mu mg$
where
$\mu=0.4$ is the coefficient of kinetic friction
$mg=400 N$ is the weight of the block.

Substituting these values, we find the magnitude of the force F:
$F=F_f = \mu mg=(0.4 )(400 N)=160 N$

4 0

3 years ago

Water is discharged from a pipeline at a velocity v (in ft/sec) given by v = 1306p(1/2), where p is the pressure (in psi). If th

shepuryov [24]

Answer:

$a=38.5 ft/sec^{2}$