Question

a moving body of 30 kg has 60 joule of kinetic energy calculate the speed
please explain fast very urgent.

The denominator of a rational number is greater than its numerator by 4. If the numerator is increased by 7 and denominator is decreased by 2 ,the new number brcomes 6/5. Find the original number​

Answer 1

Answer:

1. 2m/s    2. $\frac{33}{40}$

Explanation:

1. mass=30kg

kinetic energy=60j

velocity=x

kinetic energy =$\frac{1}{2}mv^{2}$

60= $\frac{1}{2}$ x30 x $x^{2}$

$x^{2}$=$\frac{60}{15}$

x=$\sqrt{4}$

x= 2m/s

2. let the fraction be$\frac{x}{y}$

y= x+4

$\frac{6}{5}$= $\frac{x+7}{x+4-2}$

cross multiply

5(x+7)=6(x+2)

5x+35=6x+2

35-2=6x-5x

x= 33

y= x+4

y= 33+4

=40

so $\frac{x}{y}$

$\frac{33}{40}$