Answer:
Choice a. 1 kg, assuming that all other forces on the object (if any) are balanced.
Explanation:
By Newton's Second Law,
,
where
is the acceleration of the object in
,
is the net force on the object in Newtons, and
is the mass of the object in kilograms.
As a result,
.
Assume that all other forces on this object are balanced. The net force on the object will be
. The net force is constant. Acceleration should also be constant and the same as the average acceleration in the two seconds.
<h3>What is the
average acceleration of this object?</h3>
.
.
<h3>Apply Newton's Second Law to find the mass of the object.</h3>
.
Answer: 2000 watts
Explanation:
Given that,
power = ?
Weight of object = 200-N
height = 4 m
Time = 4 s
Power is the rate of work done per unit time i.e Power is simply obtained by dividing work by time. Its unit is watts.
i.e Power = work / time
(since work = force x distance, and weight is the force acting on the object due to gravity)
Then, Power = (weight x distance) / time
Power = (200N x 4m) / 4s
Power = 8000Nm / 4s
Power = 2000 watts
Thus, 2000 watts of power is needed to lift the object.
This statement is true. The greater the mass is in an object, it is indeed the higher resistance to a change in movement the object will have. That only mean that the mass of an object and its resistance to change of movement is directly proportional.