Answer: Hand span
Explanation: Hand span is not a standard unit.
Second is the unit of time.
Meter is the unit of length or distance covered by an object.
Gram is the unit of weight of an object.
Hand span is not a standard unit. This is because the size of hand varies from person to person. Hence, the correct option is (c) "hand span".
Answer: The minimum kinetic energy Kmin is 1.3 × 10^-13 J
Explanation: Please see the attachments below
ANOTHER RUNNING DOG
Explanation:
In the given question it is to find a suitable reference point to describe the motion of dog. Here I could suggest that it is better to compare the dog with another running dog to create the relative speed difference to get a reliable motion variation.
Because the motion of dog is in the linear with respect to the another dog and to the acceleration produced by the dog in the required interval is easy to calculate with respect to another dog which is already in motion.
Hence, I suggest that Motion of dog can be analysed better by analyse the motion variation of dog with another dog running.
348.34 m/s. When Superman reaches the train, his final velocity will be 348.34 m/s.
To solve this problem, we are going to use the kinematics equations for constant aceleration. The key for this problem are the equations
and
where
is distance,
is the initial velocity,
is the final velocity,
is time, and
is aceleration.
Superman's initial velocity is
, and he will have to cover a distance d = 850m in a time t = 4.22s. Since we know
,
and
, we have to find the aceleration
in order to find
.
From the equation
we have to clear
, getting the equation as follows:
.
Substituting the values:

To find
we use the equation
.
Substituting the values:

Having your space clean. have on close toed shoes. have your hair pulled back into a ponytail. keep ur work space clean. wear gloves and goggles. do not have on droopy clothes. follow the steps on the board and double check them.