What is the speed of light ?

In a pickup game of dorm shuffleboard, students crazed by final exams use a broom to propel a calculus book along the dorm hallw

RSB [31]

Answer:

The coefficient of kinetic is

$u_{k}=0.59$

Explanation:

The forces in the axis 'x' and 'y' using law of Newton to find coefficient of kinetic friction

ΣF=m*a

ΣFy=W-N=0

ΣFy=Fn-Fu=m*a

$F_{u} =u_{k} *N\\F_{N}=25N\\N=W\\N=3.5kg*9.8\frac{m}{s^{2} }=34.3N$

$F_{N}-F_{u}=m*a\\F_{N}-u_{k}*N=m*a\\u_{k}*N=F_{N}-m*a\\u_{k}=\frac{F_{N}-m*a}{N}$

Now to find the coefficient can find the acceleration using equation of uniform motion accelerated

$v_{f} ^{2}=v_{o}^{2}+2*a(x_{f}-x_{o})\\x_{o}=0\\v_{o}=0\\v_{f} ^{2}=2*a*x_{f}\\a=\frac{v_{f} ^{2}}{2*a*x_{f}}\\ a=\frac{(1.53\frac{m}{s} )^{2}}{2*0.91m}\\a= 1.28 \frac{m}{s^{2} }$

So replacing the acceleration can fin the coefficient:

$u_{k}=\frac{F_{N}-m*a }{N}\\u_{k}=\frac{25N-(3.5kg*1.28\frac{m}{s^{2}} }{34.3N} \\u_{k}=0.59$

5 0

3 years ago

Calculate the force of gravity between a 2.50 kg newborn baby and a 80.0 kg doctor standing 0.250 m away. G = 6.67 E -11 N*m2/kg

Alex787 [66]

Answer: 2.13 × 10⁻⁷ N

Explanation:

Gravitational force exists between any two bodies having mass.

Force of gravity is given by:

$F =G\frac{Mm}{r^2}$

It is given that, mass of newborn baby is M = 2.50 kg

Mass of the doctor, m = 80.0 kg

Distance between the two, r = 0.250 m

Gravitational constant, G = 6.67 × 10⁻¹¹ N m²/kg²

⇒F = (6.67 × 10⁻¹¹ N m²/kg² × 2.50 kg × 80.0 kg )÷ (0.250 m)² = 2.13 × 10⁻⁷ N

Thus, the force of gravity between new born baby and doctor is 2.13 × 10⁻⁷ N.

7 0

3 years ago

As the frequency of a wave increases the wavelength.

zaharov [31]

Answer:

decreases

Explanation:

Remeber:

There is always inverse relation between frequency and wavelength.

So if one of them increases, other decreases and vice-versa.

f ∝ 1 / λ

4 0

2 years ago

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In an experiment, a disk is set into motion such that it rotates with a constant angular speed. As the disk spins, a small spher

boyakko [2]

Answer:

L₀ = L_f , K_f < K₀

Explanation:

For this exercise we start as the angular momentum, with the friction force they are negligible and if we define the system as formed by the disk and the clay sphere, the forces during the collision are internal and therefore the angular momentum is conserved.

This means that the angular momentum before and after the collision changes.

Initial instant. Before the crash

L₀ = I₀ w₀

Final moment. Right after the crash

L_f = (I₀ + mr²) w

we treat the clay sphere as a point particle

how the angular momentum is conserved

L₀ = L_f

I₀ w₀ = (I₀ + mr²) w

w = $\frac{I_o}{I_o + m r^2}$ w₀

having the angular velocities we can calculate the kinetic energy

starting point. Before the crash

K₀ = ½ I₀ w₀²

final point. After the crash

K_f = ½ (I₀ + mr²) w²

sustitute

K_f = ½ (I₀ + mr²) ( $\frac{I_o}{I_o + m r^2}$ w₀)²

Kf = ½ $\frac{I_o^2}{ I_o + m r^2}$ w₀²

we look for the relationship between the kinetic energy

$\frac{K_f}{K_o}$ = $\frac{I_o}{I_o + m r^2}$

$\frac{K_f}{K_o } < 1$

K_f < K₀

we see that the kinetic energy is not constant in the process, this implies that part of the energy is transformed into potential energy during the collision

6 0

2 years ago

What are some ways you can vary your tone of voice to help you communicate effectively with others? A. Speaking aggressively

Leno4ka [110]

The answer is D, talking more loudly or quietly.
<span>
An expressive voice can bring totally different meaning to what you are saying. If you speak in a monotone voice, you are implying that you do not care about what you are saying or what the other person is talking about. If you speak expressively with some parts quieter or louder to make a point, it lets the listener know that you care about what you are saying and you care about what they have to say too. You can also emphasize a point by speaking louder or indicate that something is not as important by speaking softer.</span>

7 0

3 years ago

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What is the speed of light ?​

What is the speed of light ?