First, foremost, and most critically, you must look at the graph, and critically
examine its behavior from just before until just after the 5-seconds point.
Without that ability ... since the graph is nowhere to be found ... I am hardly
in a position to assist you in the process.
Answer:
2943 J
Explanation:
Potential energy = mass x acceleration due to gravity x height in meters
(P.E. = mgh)
Substitute the given numbers: (I take acceleration due to gravity as 9.81 m s^-2)
PE = 40 x 9.81 x (0.15x50)
PE = 2943 J
B) 14.0 N
The way to solve this problem is to determine the kinetic energy the box had before and after the rough patch of floor. The equation for kinetic energy is:
E = 0.5 M V^2
where
E = Energy
M = Mass
V = velocity
Substituting the known values, let's calculate the before and after energy.
Before:
E = 0.5 M V^2
E = 0.5 13.5kg (2.25 m/s)^2
E = 6.75 kg 5.0625 m^2/s^2
E = 34.17188 kg*m^2/s^2 = 34.17188 joules
After:
E = 0.5 M V^2
E = 0.5 13.5kg (1.2 m/s)^2
E = 6.75 kg 1.44 m^2/s^2
E = 9.72 kg*m^2/s^2 = 9.72 Joules
So the box lost 34.17188 J - 9.72 J = 24.451875 J of energy over a distance of 1.75 meters. Let's calculate the loss per meter by dividing the loss by the distance.
24.451875 J / 1.75 m = 13.9725 J/m = 13.9725 N
Rounding to 1 decimal place gives 14.0 N which matches option "B".
Answer:
The speed of the aircraft relative to the ground is 606.9 
Explanation:
x-y coordinate system:
x is Positive due East direction. Similarly y is Positive due North Direction.
Now let us Decompose each vector into x-y
500 km/h due east = (500, 0)
120 km/h at 30 degree north of east
= 
= 
= 
Adding the vectors.
=
=
=
=
= (603.8, 60)
Returning back to polar form
Magnitude = 
Answer: c) The line shows a change in speed if its angle changes.
I'm not sure
Explanation: