<h2>Astronaut travels to different planets - Option 4 </h2>
If an astronaut travels to different planets, none of the planets will the astronaut’s weight be the same as on Earth. On jupiter, weight will be more than the weight on earth. For instance if an astronaut has 100kg on earth then he will have 252 kg on jupiter.
On Mars, weight will be less than the weight on the earth. For instance, if an astronaut has 68 kg on earth then he will has 26 kg on mars. On Mercury, weight of an astronaut will be less than the weight on earth. Example if he has 68 kg on earth then he will have 25.7kg on mercury.
Hence, none of these planets the weight of astronaut will be same as on earth.
The "objective" (lens or mirror) is the major major major part of
the optical telescope. It's really the only part you need in order
to make a telescope (besides something to hold the objective).
You can put a piece of film or a CCD right at the focal point of
the objective lens or mirror and capture 'images' (pictures) there.
If you want to use the telescope for looking through and seeing stuff
with your eye, then you need the other major part ... the eyepiece lens.
Answer:
It often happens in a circuit which was conducting,and a switch is opened. Any inductance in the circuit will help the voltage increase due to back emf,and this can cause breakdown of the air insulation and an arc can form.
Explanation:
Answer: 
Explanation:
The angular diameter
of a spherical object is given by the following formula:

Where:
is the actual diameter
is the distance to the spherical object
Hence:

This is the angular diameter
Answer:
Explanation:
The acceleration of gravity is 9.8m/s^2.
So to calculate the time it will take to make the ball stop(which btw means the ball now reach its greatest height), use the formula V1=V0+at. V1 is the final velocity(which is 0), V0 is the starting velocity(which is 30m/s), and the a(cceleration) is 9.8m/s^2.
(You can ignore the fact "at" is -30 instead 30, it's because the directions two velocity travel are opposite. )
We can now know the time it takes to make the ball stop just by the gravitational force is about 3 sec.
Use another formula S=1/2at^2, to find out the S(height) is 1/2*9.8*3^2=44.1, which is approximately D.45m .