Answer:
D
Explanation:
We know the formula for Work to be:
W = f * d
Where W is work done
f is force
d is the distance
A)
Work = 50
Distance = 50
So, Force is:
Force = 50/50 = 1
B)
Work = 400
Distance = 80
Force = 400/80 = 5
C)
Work = 365
Distance = 73
Force = 365/73 = 5
D)
Work = 144
Distance = 16
Force = 144/16 = 9
Hence, D is the situation in which the force applied is the greatest.
Answer:
a balance and a beaker of water
Explanation:
The mass can easily be measured with balance. If you drop the key in a beaker of water, the water inside the beaker will increase and this increases the volume of water that will be equal to volume of key.
B, since it is the only one that actually conserves matter for certain. In each of the others, matter could still be imbalanced, since for A, for example, it could be 5 Carbons on the right and 5 Chlorines on the left, and that would not balance.
Answer:
v = 0.99 c = 2.99 x 10⁸ m/s
Explanation:
From the special theory of relativity:

where,
v = speed of travel = ?
c = speed of light = 3 x 10⁸ m/s
t = time measured on earth = 90 years
t₀ = time measured in moving frame = 6 months = 0.5 year
Therefore,

<u>v = 0.99 c = 2.99 x 10⁸ m/s</u>