Answer:
ma = 48.48kg
Explanation:
To find the mass of the astronaut, you first calculate the mass of the chair by using the information about the period of oscillation of the empty chair and the spring constant. You use the following formula:
(1)
mc: mass of the chair
k: spring constant = 600N/m
T: period of oscillation of the chair = 0.9s
You solve the equation (1) for mc, and then you replace the values of the other parameters:
(2)
Next, you calculate the mass of the chair and astronaut by using the information about the period of the chair when the astronaut is sitting on the chair:
T': period of chair when the astronaut is sitting = 2.0s
M: mass of the astronaut plus mass of the chair = ?
(3)
Finally, the mass of the astronaut is the difference between M and mc (results from (2) and (3)) :

The mass of the astronaut is 48.48 kg
It depends most on the temperature of the gas.
Answer:
What are some ways we can improve on our land use?
- Avoid deforestation and close the forest frontier.
The first-order priority is to end deforestation by closing the "forest frontier" or intact forests, to development.
- Increase agricultural productivity.
- Restore forests and landscapes.
- Reduce food loss and waste.
- Improve diets
Answer:
Ultraviolet radiation would yield more electrical energy
Explanation:
The reason for the ultraviolet to generate more energy is that there would be getting more electrons per unit of time the photovoltaic cell, due to the higher frequency of the ultraviolet in comparison with the infrared radiation.
The infrared spectrum goes from 300 GHz (10^9 Hertz) to 400 THz or (10^12 Hertz).
The ultraviolet spectrum goes from 800 THz to 30.000 THz or (10^12 Hertz). This kind of radiation is responsible for skin burn from the sun and it´s the “ most usable” part from the sunlight in a photovoltaic cell.
Explanation:
The total energy of an aircraft flying in the atmosphere can be calculated using equation 1. [2]
E = ½ m v2 + mgh
A Boeing 737-300 has a maximum takeoff weight of 5.65 × 104 kg, a cruise altitude of h = 10,195 m, and cruise speed of 221 m/sec. Inserting these numbers into the above equation, we obtain 7.03 GJ for the energy at cruise conditions. [3] However, the engines mounted onto the wings of the plane are required to provide additional energy per time, power, in order to keep the aircraft flying at a constant altitude and speed
Work is the energy needed to apply a force to move an object a particular distance, where force is parallel to the displacement. Power is the rate at which that work is done.