All categories

2 years ago

Tim, with mass 53.5 kg, climbs a gymnasium

Physics

1 answer:

Stella [2.4K]2 years ago

7 0

Potential energy = mgh

= 53.5 x 9.8 x 4.7

= 2464.21 Joules

You might be interested in

A sodium atom will absorb light with a wavelength near 589 nm if the light is within 10 MHz of the resonant frequency. The atomi

Troyanec [42]

Answer:

i)20369 photons

ii) 40 ps

Explanation:

Momentum of one Sodium atom:

$P=m*v =600m/s*23amu*\frac{1 kg}{6.02*10^{23}amu}\\P=2.29*10^{-23}kgm/s$

In other to stop it, it must absorb the same momentum in photons:

$P=2.29*10^{-23}kgm/s=n_{photons}*\frac{h_{planck}}{\lambda}\\=n*\frac{6.63*10^{-34}}{589*10^{-9}} \\==>n=20369 photons$

Now, for the minimun time, we use the speed of light and the wavelength. For the n photons:

$t=n*T=n*\frac{\lambda}{c} =20369*\frac{589nm}{3*10^{8}m/s}=4*10^{-11} second=40 ps$

7 0

2 years ago

A current of 5 A is flowing in a 20 mH inductor. The energy stored in the magnetic field of this inductor is:_______

Kipish [7]

Answer:

C. 0.25J

Explanation:

Energy stored in the magnetic field of the inductor is expressed as E = 1/2LI² where;

L is the inductance

I is the current flowing in the inductor

Given parameters

L = 20mH = 20×10^-3H

I = 5A

Required

Energy stored in the magnetic field.

E = 1/2 × 20×10^-3 × 5²

E = 1/2 × 20×10^-3 × 25

E = 10×10^-3 × 25

E = 0.01 × 25

E = 0.25Joules.

Hence the energy stored in the magnetic field of this inductor is 0.25Joules

7 0

3 years ago

An aircraft maintenance technician walks past a tall hangar door that acts like a single slit for sound entering the hangar. Out

Sphinxa [80]

Answer:

The first minimum would be observed at 41.57°

Explanation:

v = 340m/s = speed of sound

f = 610Hz

d = 0.840m

λ = ?

Mλ = wsinθ

m = mth order minima

λ = wavelength incident on the single slit

θ = angular position of the mth minima

But, λ = v / f

λ = 340 / 610 = 0.557m

θ = sin⁻(mλ/d)

θ = sin⁻ [(1 * 0.557) / 0.840]

θ = sin⁻ 0.6635

θ = 41.57°

The first minimum would be observed at 41.57°

4 0

3 years ago

A 10 kg bear is running to the right at 10 m/s. He crashes into another 10 kg bear running to the left at -5 m/s. They collide a

faust18 [17]

Answer:

<em>Total momentum is conserved</em>

Explanation:

<u>Conservation of Momentum </u>

The momentum is a physical magnitude that measures the product of the object's velocity by its mass. The total momentum of a system is the sum of all its components' individual momentums. The two-bear system starts with a total moment of

$p=m_1v_1+m_2v_2=(10)(10)+(10)(-50)=50\ kg.m/s$

When both bears stick together, the total mass is 20 kg, and the new momentum is

$p'=(20)(2.5)=50 \ kg.m/s$

We have assumed both bears move to the right after the collision. In this situation, the total momentum is conserved

7 0

3 years ago

How much mass should be attached to a vertical ideal spring having a spring constant (force constant)of 39.5 N/m so that it will

nordsb [41]

Answer:

m = 1 kg

Explanation:

Given that,

The force constant of the spring, k = 39.5 N/m

The frequency of oscillation, f = 1 Hz

The frequency of oscillation is given by the formula as formula as follows :

$f=\dfrac{1}{2\pi}\sqrt{\dfrac{k}{m}} \\\\f^2=\dfrac{k}{4m\pi^2}\\\\m=\dfrac{k}{4\pi^2 f^2}\\\\m=\dfrac{39.5}{4\pi^2 \times (1)^2}\\\\m=1\ kg$

So, the mass that is attached to the spring is 1 kg.

6 0

2 years ago