It’s measured in a reference frame that is usually the earth’s surface
Answer:
a. by moving the book without acceleration and keeping the height of the book constant
Explanation:
FOR CONSTANT KINETIC ENERGY:
The kinetic energy of a body depends upon its speed according to its formula:
ΔK.E = (1/2)mΔv²
So, for Δv = 0 m/s
ΔK.E = 0 J
So, for keeping kinetic energy constant, the books must be moved at constant speed without acceleration.
FOR CONSTANT POTENTIAL ENERGY:
The potential energy of a body depends upon its height according to its formula:
ΔP.E = mgΔh
So, for Δh = 0 m/s
ΔP.E = 0 J
So, for keeping potential energy constant, the books must be moved at constant height.
So, the correct option is:
<u>a. by moving the book without acceleration and keeping the height of the book constant</u>
Answer:
3.42N
Explanation:
*not too sure bc i left my physics notes at school so it might not be 100% accurate :p*
Use the equation: F = (GMm)/(r^2)
F = force of gravity
G = gravitational constant (6.7x10^-11)
M = mass1 (2.5x10^30kg)
m = mass2 (1kg)
r = radius (7000m)
Plug it in: F = ((6.7x10^-11)(2.5x10^30)(1)) / (7000^2)
F = (1.675x10^20) / (4.9x10^7)
F = 3.4183673x10^12
F = 3.42N
If the force and the motion are along the same direction (like it is here) then work is force*distance. The time doesn't come into play until you want the power used. So here
W=9.0*3.0=27J
Answer:
Systematic errors.
Explanation:
The density of the aluminium was calculated by a human and this is not natural but can be due to errors in the calibration of the scale for measuring the weight or taking readings from the measuring cylinder.
Random errors are natural errors. Random errors in experimental measurements are caused by unknown and unpredictable changes in the experiment. Systematic errors are due to imprecision or problems with instruments.
