Answer:False
Explanation:
Work is being done on a body when it causes displacement of body on the application of force

When we pull the door by a force it causes zero displacements of the door. So we can say that work done on it is zero.
Thus the above-given statement is false
Answer:
The best estimate of the depth of the well is 2.3 sec.
Explanation:
Given that,
Record time,





We need to find the best estimate of the depth of the well
According to record time,
We can write of the record time





Here, all time is nearest 2.3 sec.
So, we can say that the best estimate of the depth of the well is 2.3 sec.
Hence, The best estimate of the depth of the well is 2.3 sec.
Answer:
Y = 3.87 x 10⁻³ m = 3.87 mm
Explanation:
This problem can be solved by using Young's double-slit experiment formula:

where,
Y = fringe spacing = ?
L = slit to screen distance = 2 m
λ = wavelength of light = 580 nm = 5.8 x 10⁻⁷ m
d = slit width = 0.3 mm = 3 x 10⁻⁴ m
Therefore,

<u>Y = 3.87 x 10⁻³ m = 3.87 mm</u>
Answer: D
Height of marble from ground
Explanation:
From the formula of kinetic energy and potential energy,
K.E = 1/2mv^2
While
P.E = mgh
From all the parameters given from the question. You can see that mass is constant, acceleration due to gravity is also constant.
Independent variable must be a value that can varies.
Since Jack rolled a marble down a ramp and recorded the potential energy and kinetic energy of the marble at different positions on the ramp to see the effects on both energies.
This different position must be the height which will produce an effect on the potential and kinetic energy of the marble.
Independent variable always provides an effect for dependent variable. Which are kinetic energy and potential energy in this case.
Height of marble from ground is the right answer.
Answer:
c
Explanation:
because I've had this question before and got it right