Question

The kinetic energy k of an object in joules is given by the formula k = 1 mv2, where m is the object's mass in kilograms and v is its velocity in meters per second. An object's velocity is 20 meters per second and its kinetic energy is 48,000 joules. If it speeds up to 30 meters per second, then what is its new kinetic energy?​

Answer 1

Answer:

108,000 joules

Explanation:

Kinetic energy, k = 1/2 mv^2

Where,

m = mass of the object in kilogram

v = velocity in meters per seconds

If

Velocity of an object = 20 meters per seconds

Kinetic energy = 48,000 joules

Solve for m

k = 1/2 mv^2

48,000 = 1/2 × m × 20^2

48,000 = 1/2 × m × 400

48,000 = 200m

m = 48,000 / 200

m = 240 kg

If it speeds up to 30 meters per second, then what is its new kinetic energy?

k = 1/2 mv^2

Using m = 240 kg

k = 1/2 mv^2

= 1/2 × 240 × 30^2

= 1/2 × 240 × 900

= 216,000 / 2

= 108,000 joules

The new kinetic energy = 108,000 joules

Explanation:

Answer 2

108,000 joules

Explanation:

Kinetic energy, k = 1/2 mv^2

Where,

m = mass of the object in kilogram

v = velocity in meters per seconds

If

Velocity of an object = 20 meters per seconds

Kinetic energy = 48,000 joules

Solve for m

k = 1/2 mv^2

48,000 = 1/2 × m × 20^2

48,000 = 1/2 × m × 400

48,000 = 200m

m = 48,000 / 200

m = 240 kg

If it speeds up to 30 meters per second, then what is its new kinetic energy?

k = 1/2 mv^2

Using m = 240 kg

k = 1/2 mv^2

= 1/2 × 240 × 30^2

= 1/2 × 240 × 900

= 216,000 / 2

= 108,000 joules

The new kinetic energy = 108,000 joules