Answer:
-8.04 m/s2
Explanation:
To find the answer to this, you have to use the 4th kinematic equation:

You plug into the equation to get:

solve for a to get
-8.04 m/s2
Answer:
Gravity and
Air resistance
Explanation:
The two forces acting on a skydiver are gravitational force and air resistance.
Gravitational force is a force that tends to pull all massive bodies towards the center of the earth. It works on all bodies that has mass. The larger or bigger the mass, the more the pull of gravity on the body.
Air resistance is the drag of air on a body as it passes to it. It is resisting force.
- When a sky diver jumps out of a plane, he/she encounters both gravity and air resistance.
- It soon balances both force and attain terminal velocity.
- Air resistance is a frictional force that opposes motion.
- This frictional force pushes in the opposite direction of motion
- Motion direction is downward due to the celerity caused by gravity.
Answer : The energy of one photon of hydrogen atom is, 
Explanation :
First we have to calculate the wavelength of hydrogen atom.
Using Rydberg's Equation:

Where,
= Wavelength of radiation
= Rydberg's Constant = 10973731.6 m⁻¹
= Higher energy level = 3
= Lower energy level = 2
Putting the values, in above equation, we get:


Now we have to calculate the energy.

where,
h = Planck's constant = 
c = speed of light = 
= wavelength = 
Putting the values, in this formula, we get:


Therefore, the energy of one photon of hydrogen atom is, 
Answer:
Explanation:
Speed = distance / time
Velocity = displacement / time
So ,
Speed = 50 km / 0.5 hr = 100 km/h
Velocity = 40 km / 0.5hr = 80 km/h