Oh my gosh ! Resisting the force of gravity always DOES involve doing work.
If no work is being done, then you're NOT resisting the force of gravity.
Example:
-- ball rolling on the floor . . . no work
-- ball rolling up a ramp . . . work being done
-- ball rolling down a ramp . . . work being done, BY gravity
Answer:
2 m/s
Explanation:
From the conservation of momentum, the initial momentum of the system must be equal to the final momentum of the system.
Let the 10.00 kg mass be
and the 12.0 kg mass be
. When they collide and stick, they have a combined mass of
.
Momentum is given by
. Set up the following equation:
, where
is the desired final velocity of the masses.
Call the right direction positive. To indicate the 12.0 kg object is travelling left, its velocity should be substitute as -8.00 m/s.
Solving yields:

Answer:
Explanation:
If you drop a ball from
the top of a building it
gains speed as it falls.
• Every second, its
speed increases by
10 m/s.
• Also it does not fall
equal distances in
equal time intervals
• If the acceleration = 0 then the velocity is
constant. [remember that acceleration is
the rate of change of velocity]
• In this case the distance an object will
travel in a certain amount of time is given
by distance = velocity x time
• For example, if you drive at 60 mph for
one hour you go 60 mph x 1 hr = 60 mi.
Answer:
It will travel 45 km (45000 m)
Explanation:
25 minutes is equal to 1500 seconds (25*60=1500)
distance=speed*time
distance=30m/s * 1500s = 45000 m = 45 km
Answer:
The correct answer is option 'a': It decreases with increase in altitude
Explanation:
Acceleration due to gravity is the acceleration that a body is subjected to when it is freely dropped from a height from surface of any planet, ignoring the resistance that the object may face in it's motion such as drag due to any fluid.. The acceleration due to gravity is same for all the objects and is independent of their masses, it only depends on the mass of the planet and the radius of the planet on which the object is dropped. it's values varies with:
1) Depth from surface of planet.
2)Height from surface of planet.
3) Latitude of the object.
Hence it neither is a fundamental quantity nor an universal constant.
The variation of acceleration due to gravity with height can be mathematically written as:

where,
R is the radius of the planet
is value of acceleration due to gravity at surface.
hence we can see that upon increase in altitude the value of 'g' goes on decreasing.