Here's the part you need to know:
(Weight of anything) =
(the thing's mass)
times
(acceleration of gravity in the place where the thing is) .
Weight = (mass ) x (gravity) .
That's always true everywhere.
You should memorize it.
For the astronaut on Saturn . . .
Weight = (mass ) x (gravity) .
Weight = (68 kg) x (10.44 m/s²)
= 709.92 newtons .
__________________________________
On Earth, gravity is only 9.8 m/s².
So as long as the astronaut is on Earth, his weight is only
(68 kg) x (9.8 m/s²)
= 666.4 newtons .
Notice that his mass is his mass ... it doesn't change
no matter where he goes.
But his weight changes in different places, because
it depends on the gravity in each place.
Answer:
Explanation:
mass of the fellow ( m ) = 66kg
acceleration of fellow a
v = u + at
4.5 = 0 + a x 2
a = 4.5 /2
= 2.25 m / s²
Net force acting on fellow in upward direction by the surface of elevator
R - mg where R is reaction force of the surface of the elevator
Applying Newton's law of motion
R - mg = ma
R = m (g +a )
= 66 x ( 9.8 + 2 )
= 778.8 N
This will be the scale reading .
Acceleration is in the direction of motion
"Light year" is a distance, not a speed. It's the distance light travels in one year, at the speed of 299,792,458 meters per second.
