What is its kinetic energy, speed, total work.?

Question

Hi, my book is horrible at explaining things, I have a test tomorrow I'm studying for, could someone solve this so I can use it to study? thanks

A 0.58 kg particle has a speed of 2.0 m/s at point A and kinetic energy of 7.5 J at point B.

(a) What is its kinetic energy at A?
J
(b) What is its speed at point B?
m/s
(c) What is the total work done on the particle as it moves from A to B?
J

Answer 1

kinetic energy = (mv^2)/2
so a) 0.58kg * 2.0^2m/s / 2 = 1.16J

b) 7.5J = 0.58kg * v^2 / 2
isolate v to find v = around 5m/s

c) Ei - Ef = W
in this case we only have kinetic energy so
mv1^2/2 - mv2^2/2 = W
we have both values of energies so
1.16J - 7.5K = -6.34J
so 6.34J was DONE on the particle

Answer 2

Kinetic Energy:
· Energy that a moving object has due to its motion is Kinetic Energy.

KE = 1/2mv2 (1/2 mass x velocity squared)

(.5 x .58kg) x (2.0m/s^2) = 1.16joule

Answer 3

The important formula here is KE = 0.5*m*v^2. In part a) you have m and v (0.58kg and 2.0m/s). Plug those number into the formula to get KE. With those units, the answer will be in J.

For b) solve the formula for v: v = √[2*KE/m]; you have KE and m, solve for v.

The work done will be the difference between the KE at A and the KE at B.