Potassium goes to argon so that a proton in the K nucleus "vanishes" into a positron (positive electron ?) but keeps the same atomic mass at 38. ? I'd say that the number of the positron was 0, and the charge was +1 electronic charge.

4 0

2 years ago

A car slows down at -5.00 m/s² until it comes to a stop after travelling 15.0 m. What was the initial speed of the car?

lapo4ka [179]

<h2>Answer: 12.24m/s</h2>

According to <u>kinematics</u> this situation is described as a uniformly accelerated rectilinear motion. This means the acceleration while the car is in motion is constant.

Now, among the equations related to this type of motion we have the following that relates the velocity with the acceleration and the distance traveled:

$V_{f}^{2}-V_{o}^{2}=2.a.d$ (1)

Where:

$V_{f}$ is the Final Velocity of the car. We are told "the car comes to a stop after travelling", this means it is 0.

$V_{o}$ is the Initial Velocity, the value we want to find

$a$ is the constant acceleration of the car (the negative sign means the car is decelerating)

$d$ is the distance traveled by the car

Now, let's substitute the known values in equation (1) and find $V_{o}$ :

$0-V_{o}^{2}=2(-5m/{s}^{2})(15m)$ (2)

$-V_{o}^{2}=-150{m}^{2}/{s}^{2}$ (3)

Multiplying by -1 on both sides of the equation:

$V_{o}^{2}=150{m}^{2}/{s}^{2}$ (4)

$V_{o}=\sqrt{150{m}^{2}/{s}^{2}}$ (5)

Finally:

$V_{o}=12.24m/s$ >>>This is the Initial velocity of the car

5 0

2 years ago

In which situation is the acceleration of the car negative?

Schach [20]

B) The velocity of a car reduced from 50 km/h to 35 km/h over one minute

6 0

2 years ago

Read 2 more answers

A stone is thrown from a cliff and lands in the sea. Air resistance is negligible. Which statement is correct whilst the stone i

erik [133]

Since the stone is travelling, the displacement cannot be constant. This leaves the last 2 choices as possibilities. Now consider the acceleration that can act on the stone. Acceleration due to gravity is the only one. That means the horizontal component of the stone has to be constant since there is no acceleration in the horizontal direction.

4 0

3 years ago