F = (mass)(acceleration) = ma
m = 0.25 kg
Vi = 16 m/s
t = 2 s
Vf = 0 m/s (since it was put to stop)
a=(Vf-Vi)/t
a=(0-16)/2
a = 8 m/s^2 (decelerating)
F = ma = (0.25 kg)(8 m/s^2)
F = 2 N
<span>Hope
this answer will be a good h<span>elp for you.</span></span>
Answer:C
Explanation:
Power=280watts=280/1000 kilowatts
Power=0.28 kilowatts
Device use 0.28 kilowatts in 1 day
1day=24hours
Device use 0.28 kilowatts in 24hours
30days=30 x 24=720 hours
For 720 hours=(0.28x720) ➗ 24
For 720 hours=201.6 ➗ 24
For 720 hours=8.4
Answer:
The system's potential energy is -147 J.
Explanation:
Given that,
Energy = 147 J
We know that,
System is isolated and it is free from external forces.
So, the work done by the external forces on the system should be equal to zero.
We need to calculate the system's potential energy
Using thermodynamics first equation
Put the value into the formula
Hence, The system's potential energy is -147 J.
Distance covered is given as follows
1). 7 km North
2). 5 km North
3). 1 km East
Now total distance covered will be given as
Now in order to find the displacement we will show all with their directions
towards North
towards East
So total displacement is
so net displacement will be
so displacement is 12.04 km
Answer:
The correct answer is a) The kinetic energy of the ice increases by equal amounts for equal distances.
Explanation:
The law of conservation states that the energy cannot be created nor be destroyed but can be converted from one form to another.Before the ice even starts falling we already know that it possesses energy in the form of potential energy given by P=mgh where m is the mass of the ice , g is the acceleration due to gravity and h is the height of the ice above the ground whatever that may be, since a number is not given here.As the ice falls the energy is converted from potential energy to kinetic energy. We notice one thing about the equation for the potential energy P , which is that it is not only directly proportional to h but also is linear in h as well(which is the main reason why a) is correct) which means that if the ice drops by 1 meter the potential energy it will have lost would be ΔPE=mgΔh=-mg, where Δh is the change in its height which is 1 meter here.And according to the principle of conservation of energy this energy must be converted to kinetic energy so the ΔKE=-ΔPE=mg, and this process repeats and for each meter it falls, it picks up the same amount of kinetic energy equaling mg(which is the same as the loss in PE per each meter of fall). So a 2 meter decrease in height will result in an increase in KE of 2mg, a 3 meter decrease in height will result in an increase in KE of 3mg. gain in kinetic energy only depends on the drop in height, which is true irrespective of where the ice might happen to be in its journey close to the top or the bottom. So the drop in height of lets say x at any point in the journey will result in the same increase in KE = ΔKE = mgx. Which proves part a) to be correct.
