Answer:
d) The speed of the astronaut
Explanation:
The sentence describes the speed of the astronaut. This speed value is 10meters per minute.
Now let us understand why;
- Speed is the distance divided by time. It is a scalar quantity without regard for direction but it has magnitude.
- The value 10meters per minute clearly shows this instance. We do not know the direction the astronaut is moving towards.
- Velocity, like speed is the displacement of a body with time. It is a vector quantity and it shows the direction of motion.
- For example, 10m/s due west is a velocity value because we know the direction.
Therefore, since there is no directional sense, the value indicates speed.
Answer:
)Give the definition of poverty line as defined by the World Bank.
Answer:
μ = 0.18
Explanation:
Let's use Newton's second Law, the coordinate system is horizontal and vertical
Before starting to move the box
Y axis
N-W = 0
N = W = mg
X axis
F -fr = 0
F = fr
The friction force has the formula
fr = μ N
fr = μ m g
At the limit point just before starting the movement
F = μ m g
μ = F / m g
calculate
μ = 34.8 / (19.8 9.8)
μ = 0.18
<span>when it returns to its original level after encountering air resistance, its kinetic energy is
decreased.
In fact, part of the energy has been dissipated due to the air resistance.
The mechanical energy of the ball as it starts the motion is:
</span>

<span>where K is the kinetic energy, and where there is no potential energy since we use the initial height of the ball as reference level.
If there is no air resistance, this total energy is conserved, therefore when the ball returns to its original height, the kinetic energy will still be 100 J. However, because of the presence of the air resistance, the total mechanical energy is not conserved, and part of the total energy of the ball has been dissipated through the air. Therefore, when the ball returns to its original level, the kinetic energy will be less than 100 J.</span>
Answer:
The second projectile was 1.41 times faster than the first.
Explanation:
In the ballistic pendulum experiment, the speed (v) of the projectile is given by:
<em>where m: is the mass of the projectile, M: is the mass of the pendulum, g: is the gravitational constant and h: is the maximum height of the pendulum. </em>
To know how many times faster was the second projectile than the first, we need to take the ratio for the velocities for the projectiles 2 and 1:
(1)
<em>where m₁ and m₂ are the masses of the projectiles 1 and 2, respectively, and h₁ and h₂ are the maximum height reached by the pendulum by the projectiles 1 and 2, respectively. </em>
Since the projectile 1 has the same mass that the projectile 2, we can simplify equation (1):

Therefore, the second projectile was 1.41 times faster than the first.
I hope it helps you!