Clear question is;
An ice cube is placed in the sun. Later there is a puddle of water. Later still the puddle is gone. What kind of change has occurred?
Answer:
Physical change.
Explanation:
There are two type of changes called physical change and chemical change.
In Physical changes, there is only change in the appearance of the substance and not its chemical composition. Whereas, in Chemical changes the substance changes entirely into another substance with a new chemical formula.
Now, for the ice cube, it has melted from a solid state to a liquid state. Thus, there is only a change in appearance and not its chemical composition. Thus, it's a physical change that has occurred.
Answer:
Explanation:
Expression for emf induced = 1 /2 B n r²ω where B is magnetic field , r is radius of the coil and ω is angular velocity of rotation , n is no of turn .
ω = 2πf = 2π x 60 = 120 π ; where f is frequency of rotation .
emf induced = 1 /2 B r²x 120π x n
Putting the given values
10000 = .5 x B x .11² x 120 x 3.14 x 506
B = 8.67 T .
Answer:
1) Time period
2) amplitude
3) Hertz or hz
4) Noise
5) frequency
6) infrasonic and ultrasonic
7) solid liquid and gas
8) A man
9) energy
10)1 vibration per minute
I'm not sure but it's probably C because you are treating a health problem.
Answer:
9.81 N
Explanation:
Given that a baseball weighs 1 kg. The pitcher throws the ball at a velocity of 10 m/s straight up. Neglecting air resistance. The maximum height reached will be calculated by using the formula
V^2 = U^2 - 2gH
U = 10 m/s
g = 9.8m/s^2
At maximum height, V = 0
Substitute u and g into the formula
0 = 10^2 - 2 × 9.8 × H
19.6H = 100
H = 100/19.6
H = 5.1 m
The Kinetic energy on the ball will be
K.E = 1/2mv^2
K.E = 1/2 × 1 × 10^2
K.E = 1/2 × 100
K.E = 50 J
But energy = work done
WD = Force × distance (height)
The force that acts on the baseball when it is HALF WAY to the top of the path will be
F × 5.1/2 = 50
F = 100/5.1
F = 19.61 N
The weight acting downward will be
W = mg
W = 1 × 9.8
W = 9.8 N
The net force acting on the ball will be
Net force = F - W
Net force = 19.61 - 9.8
Net force = 9.81 N
Therefore, the net force that acts on the baseball when it is HALF WAY to the top of the path is 9.81 N
