A watt equals

A rock is dropped from a bridge to the water below. It takes 3.2 s for the rock to hit the water. Find the speed (in m/s) of the

Eduardwww [97]

Kinematic equations
v=at. v=9.81x3.2 v=32m/s (approx)
v^2=2axheight.
32x32/2x10=height
16x32/10 = height
height is approx 48metres

8 0

3 years ago

A 0.140-kg baseball traveling 34.0 m/s strikes the catcher's mitt, which, in bringing the ball to rest, recoils backward 19.0 cm

Eva8 [605]

Add then subtract then u will get ur answer

4 0

3 years ago

Mimi makes a table about the two types of beta decay. A 5 column table with 2 rows. The first column is labeled type of decay wi

Rina8888 [55]

Answer:

No change in mass number occurs in beta minus decay

Explanation:

4 0

3 years ago

17.Explain the different ways that an object can become electrically charged.

Debora [2.8K]

17.

There are three different methods for charging objects:

- Friction: in friction, two objects are rubbed against each other. As a result, electrons can be passed from one object to the other, so one object will gain a net negative charge while the other object will gain a net positive charge due to the lack of electrons.

- Conduction: this occurs when two conductive objects are put in contact with each other, and charges (electrons, usually) are transferred from one object to the other one.

- Induction: this occurs when two objects are brought closer to each other, but not in contact. If one of the two objects has a net charge (different from zero) on its surface, then it will induce a movement of charges in the second object: in particular, in the second object, charges of the opposite polarity will be attracted towards the first object, while charges of same polarity will be repelled further away.

18.

Charged objects produce around themselves an electric field. The strenght of the electric field is given by (assuming the charged objects are spherical)

$E=k\frac{q}{r^2}$

where k is the Coulomb's constant, q is the magnitude of the charge and r the distance from the centre of the charge. As we see, the strength of the field is inversely proportional to the square of the distance.

Also, the direction of the field is determined by the sign of the charge:

- if the charge is positive, the electric field points away from the charge (this means that other positive charges in the field will be repelled away)

- if the charge is negative, the electric field points towards the charge (this means that other positive charges in the field will be attracted towards it)

19.

Electrical force is given by:

$F=k\frac{q_1 q_2}{r^2}$

where k is the Coulomb's constant, q1 and q2 are the two charges, and r their separation.

Gravitational force is given by:

$F=G\frac{m_1 m_2}{r^2}$

where G is the gravitational constant, m1 and m2 are the masses of the two objects, and r their separation.

Similarities between the two forces:

- Both are inversely proportional to the square of the distance between the two objects, r

- Both are non-contact forces (the two objects can experience the forces even if they are not in contact)

- Both forces have infinite range

Differencies between the two forces:

- The electric force can be either attractive or repulsive, while the gravitational force is attractive only

- The electric force is much stronger than the gravitational force, due to the much larger value of the Coulomb's constant k compared to the gravitational constant G

4 0

4 years ago

What is the pressure if a force of 200 N is applied over an area of

Gelneren [198K]

The pressure is $4 N / c m^{2}$ .

Answer: Option A

<u>Explanation:</u>

Pressure defines the force acting per single area. So depending upon the amount of force acting over a given area in the perpendicular direction of the object, the pressure acting on that area will vary.

So the pressure is directly proportionate to the applied force on a particular region and inversely proportionate into the areas of the region. Hence, the unit of pressure is considered as $N / c m^{2}$ or Pascal. Pressure can also be termed as the number of air molecules present in a specified closed region. Thus, for the present condition

$\text { Pressure }=\frac{\text { Force }}{\text { Area }}$

Thus, by appling the given values in the above equation, we get,

$\text { Pressure }=\frac{200}{50}$ = $4 N / c m^{2}$

So the pressure is $4 N / c m^{2}$ .

6 0

3 years ago