10 points

A bullet of mass 20g is horizontally fired with a velocity of 150m/s from a pistol of mass 2 kg. What is the

kiruha [24]

Answer:

m1 = 20g (= 0.02 kg)

Mass of pistol, m2 = 2 kg

Initial velocity of the bullet (u1) and pistol (u2) = 0

Final velocity of the bullet, v1 = +150m s-1

Let v be the recoil velocity of the pistol.

Total momentum of the pistol and bullet after it is fired is

= (0.02 kg x 150 m s-1) + (2 kg x v m s-1)

= (3 + 2v) kg m s-1

Total momentum after the fire = Total momentum before the fire

3 + 2v = 0

→v = -1.5 m/s

7 0

3 years ago

Two charged particles are projected into a magnetic field that is perpendicular to their initial velocities. If the charges are

Svetllana [295]

Answer:

The two charged particles are opposite charge (one positive, the other negative)

Explanation:

This can be explained through Fleming's left hand rule. As we know in Fleming's LH rule

Thumb: represent motion of the charge

Fore finger: direction of magnetic field

Centre finger: direction of current

In this case, the direction of magnetic field is in one way (perpendicular to direction of the particles motion)

If the charge is positive, equivalently it's direction is the same as the direction of current. If the charge is negative, it's direction is opposite the direction of current.

Using the fleming left hand rule, we'll see that as we change the direction of current without changing the direction of field, the direction of motion will change towards the opposite way.

For example, let's say the particles is moving away from you and the magnetic field is from left to right:

If the charge is positive (hence direction of current is away from you), the particles will move downward.

If the charge is negative (hence direction of current is toward you), the particles will move upward.

With these evidence, no doubt that the two particles have different charges.

7 0

4 years ago

A watermelon is blown into three pieces by a large firecracker. Two pieces of equal mass m fly away perpendicular to one another

Alenkinab [10]

Answer:

Speed of larger piece is $\dfrac{V\sqrt{2}}{3}$

Explanation:

We apply the principle of conservation of momentum.

The watermelon is initially at rest. The initial momentum = 0 kg m/s in all directions.

After the collision,

Vertical momentum = momentum of piece in y-direction + y-component of momentum of larger piece = $mV + 3mv_{ly}$

Here, $v_{ly}$ is the y-component of velocity of larger piece.

This is equal to 0, since the initial momentum is 0.

$v_{ly}=\dfrac{V}{3}$

Horizontal momentum = momentum of piece in x-direction + x-component of momentum of larger piece = $mV + 3mv_{lx}$

Here, $v_{lx}$ is the x-component of velocity of larger piece.

This is also equal to 0, since the initial momentum is 0.

$v_{lx}=\dfrac{V}{3}$

The velocity of the larger piece, $v_l$ , is the resultant of $v_{lx}$ and $v_{ly}$ . Since they are mutually perpendicular,

$v_l = \sqrt{v_{ly}^2+v_{lx}^2}= \sqrt{\left(\dfrac{V}{3}\right)^2+\left(\dfrac{V}{3}\right)^2}$

$v_l = \dfrac{V\sqrt{2}}{3}$

3 0

4 years ago

A current of 0.050 amps flows in a circuit element with a resistance of 100

inessss [21]

Answer:

The answer is B 5.0 Volts

Explanation:

I'm using the formula from Ohm's Law like you mentioned for my answer.

V=IR

V=0.050 amps x 100 ohms of resistance

With this you'll have your answer!

5 0

3 years ago

Read 2 more answers

During a single-replacement reaction, a more-active metal will replace a less-active metal in a compound. Which single-replaceme

son4ous [18]

Answer:

Mg will replace Ag in a compound

Explanation:

A single replacement reaction is driven by the position of ions on the activity series.

As a rule of thumb, the position of metal ions on the activity series determines their reactivity.

Metal ions that are above another are more reactive and they will displace those that are lower.

Generally, activity increases as we go up the group.

Mg ions are higher than Ag ions on the series so, Mg will displace Ag from a solution.

8 0

3 years ago