Which of the following is most needed for cosmotologists to study the age of the universe

Which scientist contributed to disproving spontaneous generation?

kompoz [17]

Answer:

A. John Tyndall

Explanation:

In 1887, John Tyndall confirmed the theory of biogenesis, formulated by Luis Pasteur in 1864, applying sterilization by discontinuous heating, a process that is currently known as tyndalization. Evidence of the existence of resting microbacterial forms, very resistant to heat.

Thanks to this demonstration he is recognized as the father of microbiology with Pasteur. The theory brought down the previous idea of the Spontaneous Generation, which remained in force since 1745.

5 0

3 years ago

A slender rod is 90.0 cm long and has mass 0.120 kg. A small 0.0200 kg sphere is welded to one end of the rod, and a small 0.080

deff fn [24]

Answer:

Speed of 0.08 kg mass when it will reach to the bottom position is 1.94 m/s

Explanation:

When rod is released from rest then due to unbalanced torque about the hinge the system will rotate

Now moment of inertia of the system is given as

$I = \frac{ML^2}{12} + \frac{m_1L^2}{4} + \frac{m_2L^2}{4}$

now we have

$M = 0.120 kg$

$m_1 = 0.02 kg$

$m_3 = 0.08 kg$

now we have

$I = \frac{0.120(0.90)^2}{12} + \frac{0.02(0.90)^2}{4} + \frac{0.08(0.90)^2}{4}$

so we have

$I = 8.1 \times 10^[-3} + 4.05 \times 10^[-3} + 0.0162$

$I = 0.02835$

now by energy conservation we can say work done by gravity must be equal to change in kinetic energy

so we have

$\frac{1}{2}I\omega^2 = m_1g \frac{L}{2} - m_2 g\frac{L}{2}$

$\frac{1}{2}(0.02835)\omega^2 = (0.08 - 0.02)(9.81)(0.45)$

$\omega = 4.32 rad/s$

Now speed of 0.08 kg mass when it reaches to bottom point is given as

$v = \omega \frac{L}{2}$

$v = 4.32 (0.45)$

$v = 1.94 m/s$

3 0

4 years ago

A 5.00 g bullet traveling 355 m/s is stopped by lodging in the side of a building. The heat produced is shared between the build

steposvetlana [31]

Answer:

Explanation:

Given

mass of bullet $m=5\ gm$

speed of bullet $v=355\ m/s$

bullet is stopped by building and heat produced is shared between building and bullet

Kinetic Energy of bullet is converted into Thermal energy

Kinetic Energy of bullet $K=\frac{1}{2}mv^2$

$K=0.5\times 5\times 10^{-3}\times (355)^2$

$K=315.06\ J$

So 315.06 J of Energy is converted in to thermal energy

7 0

3 years ago

What is the reaction force for sky diving?

DIA [1.3K]

As the skydiver accelerates she gains momentum, and the air she passes through creates a resistance that pushes back up at her, increasing drag. Eventually, the force of the resisting air balances out with the force of gravity, and the skydiver stops speeding up

7 0

3 years ago

Consider the flow of an incompressible Newtonian fluid between two parallel plates that are 4 mm apart. If the upper plate moves

marin [14]

Answer:

Net flow rate = 0.00035 m³/s

Explanation:

The speed of plate 1, U₁ = 5 m/s

The speed of plate 2, U₂ = 1.5 m/s

The two plates are moving in different directions, the net speed will be gotten by taking the difference of the average of the two plates

The average speed due to the movement of plate 1 = U₁/2 = 5/2 = 2.5 m/s

The average speed due to the movement of plate 2 = U₂/2 = 1.5/2

= 0.75 m/s

The net average speed of the fluid= U₁/2 - U₂/2

The net average speed of the fluid = 2.5 - 0.75 = 1.75 m/s

Net flow rate = Net average speed * Area of the plate

Width of the plate, v = 5 cm = 0.05 m

Distance between the plates = 4 mm = 0.004 m

Area = 0.05 * 0.004

Area = 0.0002 m²

Net flow rate = 1.75 * 0.0002

Net flow rate = 0.00035 m³/s

8 0

3 years ago