Question

what is the K.E gained by a ball of 400 g when it move with a speed of 10 ms-1​

Answer 1

Answer:

20 J

Explanation:

For the ball-

Mass, m = 400g = 0.4 Kg

Speed, v = 10 m/s

Let us consider the ball to be moving in the same direction.

Now, K.E = 1/2 mv^2

= 1/2 * 0.4 * 10 * 10

= 20 J

Answer 2

$\green{given \: : } \: mass \: of \: ball \: = \: 400g \: \: \: \: \: \: \: \: \: \\ \: \: \: \: \: velovity \: = \: 10m {s}^{ - 1}$

$\green{To \: \: find \: : } \: k.e \: \: gained \: by \: ball$

By using the formula

$\boxed{ \boxed{ \: \: \: \: \: \: \: \: \: \: \: K.E \: = \dfrac{1}{2} m {v}^{2} \: \: \: \: \: \: \: \: \: \: \: \: \: \: } }$

$\implies \: K.E \: = \frac{1}{2} \times 400 \times {(10)}^{2}$

$\implies \: K.E \: = \dfrac{1}{ \cancel{ \: 2 \: \: } } \times 400 \times { \cancel{100}}$

$\implies \: K.E \: = \: 400 \times 50$

${\implies \: K.E \: = \:200000\: \: or\: \:20 joule}$