Compare the kinetic energy of a 20,000-kg truck moving at 110 km/h with that of an 80.0-kg astronaut in orbit moving at 27,500 km/h. For this Practice Exam question, calculate the kinetic energy of the astronaut.

The kinetic energy of the astronaut is far greater than that of the truck; 2,334,111,728.4Joules

Explanation:

Given the mass of the truck to be 20000kg and its velocity to be 110km/hr, its velocity in meter/seconds will give;

110×1000m/1×3600s

= 110000m/3600s

= 30.6m/s

KE of the truck = 1/2MV²

= 1/2×20000×30.6²

KE = 9,363,600Joules

KE of truck = 9.363MJ

Similarly, given mass of the astronaut to be 80kg and velocity of 27500km/hr, converting the velocity to m/s we have:

27500×1000m/1×3600s

= 27,500,000/3600

= 7638.9m/s

Its kinetic energy will be;

KE = 1/2×80×7638.9²

KE = 2,334,111,728.4Joules

KE = 2.33GJ

The kinetic energy of the astronaut is approximately 2.33gigaJoules

This shows that the kinetic energy of the astronaut is far greater than that of the truck.

gpe = mass x gravity constant x height or… gpe = mgh

where… mass: measured in kilograms (kg)

gravity: gravity constant on earth = 10.00 m/s2

height: measured in meters (m)

gpe: measured in joules (j) or kilojoules (kj)

how do you solve gpe?

gravitational potential energy (gpe) is the energy an object has because of its position above the. ground.

gpe = mass x gravity constant x height or… gpe = mgh.

mass:

note: to earn full marks when solving science word problems, you must show your work:

formula.

example:

given values:

mass = 0.3 kg.