Which star is closest to our solar system (after the sun)? a. Vega b. Sirius c. Regulus d. Proxima Centauri

Answer:

Energy of photon,

Explanation:

It is given that,

Wavelength of photon,

It strikes a mercury atom in the ground state. We have to find the energy of this photon. It can be calculated using below relation as :

Where

h is the Planck's  constant

c is the speed of light

So,

Hence, the above value is the energy of this photon.

Answer:

You will feel more weight if it is accelerating out of the planet.

You will feel less weight if it is accelerating towards the planet.

Explanation:

The weight that you are observing or feeling is basically due to the change in acceleration of your fall or rising up in the spaceship. When the acceleration is stationary on the surface, you experience your normal weight due to the gravitational acceleration of that planet.

When the spaceship accelerates above or out of the planet you experience acceleration more than the acceleration of gravity hence more weight.

When the spaceship accelerates towards the planet you experience acceleration less than the acceleration of gravity hence less weight.

If the spaceship is free falling at the gravitational acceleration you experience a zero weight

Answer:

2m/s

Explanation:

speed = distance÷time

speed =90÷45=2m/s

Answer:

a) t=1s

y = 10.1m

v=5.2m/s

b) t=1.5s

y =11.475 m

v=0.3m/s

c) t=2s

y =10.4 m

v=-4.6m/s  (The minus sign (-) indicates that the ball is already going down)

Explanation:

Conceptual analysis

We apply the free fall formula for position (y) and speed (v) at any time (t).

As gravity opposes movement the sign in the equations is negative.:  

y = vi*t - ½ g*t2 Equation 1

v=vit-g*t  Equation 2

y: The vertical distance the ball moves at time t  

vi: Initial speed

g= acceleration due to gravity

v= Speed the ball moves at time t  

Known information

We know the following data:

Vi=15 m / s

t=1s ,1.5s,2s

Development of problem

We replace t in the equations (1) and (2)  

a) t=1s

=15-4.9=10.1m

v=15-9.8*1 =15-9.8 =5.2m/s

b) t=1.5s

=22.5-11.025=11.475 m

v=15-9.8*1.5 =15-14.7=0.3m/s

c) t=2s

= 30-19.6=10.4 m

v=15-9.8*2 =15-19.6=-4.6m/s  (The minus sign (-) indicates that the ball is already going down)

Answer : The correct option is, (D) Endothermic

Explanation :

Adiabatic : It is a process in which a heat is constant. That means no heat is lost or gained by the system.

Isothermic : It is a process in which a temperature is constant.

Exothermic : It is a process in which heat released from system to surrounding. In this process, surrounding temperature increases and system temperature decreases.

Endothermic : It is a process in which heat required from the surrounding. In this process, surrounding temperature decreases and system temperature increases.

When the temperature of water increases from room temperature to 90ºC the process of heating the water is endothermic.

Hence, the correct option is, (D) Endothermic

Answer:

From the Land to the atmosphere

From the atmosphere to space

Explanation:

Answer:

from the atmosphere to space

from the Land to the atmosphere

Explanation: