Which situation is a result of human activities

What is the wavelength of an earthquake wave if it has a speed of 4 km/s and a frequency of 7 Hz?

damaskus [11]

Answer: 0.571 km/s

λ = v/f

λ = 4/7

λ = 0.571 km/s

7 0

4 years ago

As a football player moves in a straight line [displacement (3.00 mm)i^i^ - (6.50 mm)j^j^], an opponent exerts a constant force

Brilliant_brown [7]

Answer:

Work done, $W=(0.378i-1.092j)\ J$

Explanation:

Displacement,

$d=(3i-6.5j)\ mm\\\\d=(0.003i-0.0065j)\ m$

Force, $F=(126i+168j)\ N$

Work done by the opponent do on the football player is given by :

$W=F{\cdot} d\\\\W=(126i+168j){\cdot} (0.003i-0.0065j)\ m\\\\W=(0.378i-1.092j)\ J$

So, the work done by the opponent do on the football player is $(0.378i-1.092j)\ J$ .

4 0

3 years ago

Read 2 more answers

Calculate the force between two objects that have masses of 70 kilograms and 2,000 kilograms separated by a distance of 1 meter.

Makovka662 [10]

$▪▪▪▪▪▪▪▪▪▪▪▪▪ {\huge\mathfrak{Answer}}▪▪▪▪▪▪▪▪▪▪▪▪▪▪$

The Gravitational Force between given objects will be ~

$9.34 \times {10}^{ - 6} \: \: N$

$\large \boxed{ \mathfrak{Step\:\: By\:\:Step\:\:Explanation}}$

We know that ~

$\huge\boxed{\mathrm{F = \dfrac{ Gm_1m_2}{ r²}}}$

where ~

F = gravitational force

$m_1$ = mass of 1st object = 70 kg

$m_2$ = mass of 2nd object = 2000 kg

G = gravitational constant = $6.674 × {10}^ {-11}$

r = distance between the objects = 1 m

Let's calculate the force ~

$F = \dfrac{6.674 \times 10 {}^{ - 11} \times 70 \times 2000 }{1 {}^{2} }$

$F =6.674 \times 7 \times 2 \times 10 { }^{ - 11} \times 10 {}^{4}$

$93.436 \times 10 {}^{ - 7}$

$9.3436 \times 10 {}^{ - 6} \: \: newtons$

6 0

3 years ago

Assume you need to design a hydronic system that can deliver 80,000 Btu/hr. What flow rate of water is required if the temperatu

PolarNik [594]

Answer:

At 10°F change in temperature

Mass flowrate = 1.01 kg/s = 2.227 lbm/s

Volumetric flowrate = 1010 m³/s = 35667.8 ft³/s

At 20°F change in temperature

Mass flowrate = 0.505 kg/s = 1.113 lbm/s

Volumetric flowrate = 505 m³/s = 17833.9 ft³/s

Explanation:

80000 btu/hr = 23445.7 W

P = ṁc(ΔT)

ṁ = MASS flowrate

c = specific heat capacity of water = 4182 J/kg.K,

ΔT = change in temperature = 10°F

To convert, a change of 18°F is equal to a change of 10°C

A change of 10°F = 10×10/18 = 5.556°C = 5.556K

P = ṁc(ΔT)

23445.7 = ṁ(4182 × 5.556)

ṁ = 23445.7/(4182 × 5.556)

ṁ = 1.01 kg/s = 2.227 lbm/s

In volumetric flow rate, Q = density × mass flowrate = 1000 × 1.01 = 1010 m³/s = 35667.8 ft³/s

For a change of 20°F,

ΔT = change in temperature = 20°F

To convert, a change of 18°F is equal to a change of 10°C

A change of 20°F = 20×10/18 = 11.1111°C = 11.111K

P = ṁc(ΔT)

23445.7 = ṁ(4182 × 11.111)

ṁ = 23445.7/(4182 × 11.111)

ṁ = 0.505 kg/s = 1.113 lbm/s

In volumetric flow rate, Q = density × mass flowrate = 1000 × 0.505 = 505 m³/s = 17833.9 ft³/s

Hope this Helps!!!

4 0

4 years ago

Which of the following statements about energy is false?

Artemon [7]

Answer:

c

Explanation:

5 0

3 years ago