Question

7. Calculate the change in kinetic energy of
a toy car of mass 2 kg when its speed is
raised from 8 m/s to 16 m/s.​

Answer 1

Given :

• Mass of the toy car = 2 kg
• Initial velocity (u) = 8 m/s
• Final velocity (v) = 16 m/s

To find :

• Change in kinetic energy

Solution :

Kinetic energy is the energy possesed by the object due to it's motion .

Initial Kinetic energy ,

$\leadsto KE_i = \dfrac{1}{2}mu^2$

Final kinetic energy,

$\leadsto KE_f = \dfrac{1}{2}mv^2$

Change in kinetic energy ,

$\leadsto \Delta KE = KE_f- KE_i$

$\leadsto \Delta KE = \dfrac{1}{2} m (v^2 - u^2)$

$\leadsto \Delta KE = \dfrac{1}{2} \times 2 (256 - 64)$

$\leadsto \boxed{\red{ \Delta KE = 192 J }}$

Hence ,

The change in kinetic energy is 192 J .

Answer 2

Answer:

Ans.192J

Explanation:

mass of toy car=2kg

speed=8m/s

K.E.=1/2mv2=1/2*2*8*8=64J

speed=1/2mv2=1/2*2*16*16=256J

Change= 256-64=192J