60% of 10 is 6, so 10x6 is the area which is 60ft^2
Lets say the number is ab. Its value is 10a + b
When it is reversed it is 10b + a = 12a+1.2b (from the condition its value should increase 0.2 times).
11 a = 8.8b
a/b = 8.8/11 = 0.8/1 = 8/10 = 4/5 ( we do this because a and b should be natural numbers less than 10).
answer is 45.
Answer:
1. 22583.5 J
2. 1248 kg
3. 78.09 m/s
Step-by-step explanation:
The formula for kinetic energy is ;
K.E = 1/2* m * v²
Where m is the mass and v is the velocity
1.
K.E = 1/2 * m*v²
K.E = 1/2 * 47 * 31²
K.E = 22583.5 J
2.
Velocity = 9.78 m/s.
Kinetic energy = 60,800 J
To get mass, apply the formula as;
K.E = 1/2 * m*v²
60,800 = 1/2 * m * 9.78²
60800 = 48.70845 m
60800/48.70845 = m
1248 = m
Mass = 1248 kg
3.
K.E = 143.3 J
Mass = 0.047 kg
Apply the formula;
K.E = 1/2 * m*v²
143.3 = 1/2 * 0.047 * v²
143.3 = 0.0235 v²
143.3/0.0235 = v²
6097.87 = v²
v = √6097.87
v= 78.09 m/s
and 
