Question

if a car (m=1.5kg) is moving with a speed of 10m/s and then change its speed to 15m/s what will be the increase in K.E of the car​

Answer 1

Answer:

• 93.75 Joules is the required answer .

Explanation:

Given:-

• Mass ,m = 1.5 kg
• Initial velocity ,u = 10m/s
• Final Velocity ,v = 15m/s

To Find:-

• Increase in Kinetic Energy

Solution:-

As we have to calculate the increase in Kinetic Energy

Kinetic energy is defined as the energy possess by body due to its motion.

Increase in Kinetic Energy is calculated by the Final kinetic Energy - Initial Kinetic Energy

→ KE = 1/2 mv² - 1/2mu²

Taking Common

→ KE = 1/2m (v²-u²)

→ KE = 1/2 × 1.5 ( 15² - 10²)

→ KE = 1.5/2 × (15+10) (15-10)

→ KE = 1.5/2 × 25×5

→ KE = 1.5/2 × 125

→ KE = 0.75 × 125

→ KE = 93.75 J

• Hence, the increase in Kinetic Energy is 93.75 Joules.

Answer 2

Answer:

Given :-

• Mass = 1.5 kg
• Initial Velocity = 10 m/s
• Final Velocity = 15 m/s

To Find :-

Change in kinetic energy

Solution :-

As we know that

Change in KE = ½ m (v² - u²)

=> ½ × 1.5 (15² - 10²)

=> ½ × 1.5 (225 - 100)

=> 1.5/2 (125)

=> 1.5/2 × 125

=> 0.75 × 125

=> 93.75

$\therefore {\textsf{ \underline{ \: Increase \: in \: KE }}} { \textsf{ \textbf{ \underline{9375J}}}}$