Answer:
2 m/s
Explanation:
Given that a student walks 4 blocks east, 1 blocks north, 2 block west and then 1 blocks south in an hour.
The total time = 1 hour
The vertical displacement = 1 - 1
Vertical displacement = 0
Horizontal displacement = 4 - 2
Horizontal displacement = 2
Total displacement = sqrt (2^2 - 0^2)
Total Displacement = 2
Average velocity = displacement/time
average velocity = 2 / 1
Average velocity = 2 m/s
Therefore, her average velocity is 2 metres per second.
The total heat that is needed by the water to get converted to steam is calculated below through the equation,
H = (Hv)(n)
where H is the heat, Hv is the heat of vaporization (40.67 kJ/mol), and n is the number of mols. Substituting the known values,
H = (40.66 kJ/mol)(1.5 mol) = 60.99 kJ
Calculating for the time,
t = (60990 J) / (24 J/s)
t = 2541.25 s
Answer: 2541.25 s or approximately 42.35 minutes
Grams, Milligram, Microgram.
Because they have special tool's that help them find out
Answer:
The velocity of the acorn just before it reaches the ground is 19 m/s
The kinetic energy when hitting the ground is 3.1 J
Explanation:
Given;
mass of the acorn, m = 0.017 kg
height of fall, h = 18.5 m
Apply the law of conservation of mechanical energy;
mgh = ¹/₂mv²
gh = ¹/₂v²
v² = 2gh
v = √2gh
v = √(2 x 9.8 x 18.5)
v = 19 m/s
Thus, the velocity of the acorn just before it reaches the ground is 19 m/s
Now, determine the kinetic energy when hitting the ground;
K.E = ¹/₂mv²
K.E = ¹/₂(0.017)(19)²
K.E = 3.09 J
K.E = 3.1 J
Therefore, the kinetic energy when hitting the ground is 3.1 J
