Question

A the P.E =2.4 J and K.E. = 0J, at B the K.E. is 2.0 J and at C the P.E is 0J. Calculate (i) The P.E. at B (ii) The K.E. at C (iii) The K.E. and P.E. at D​

Answer 1

Explanation:

(i) The potential energy at B can be calculated as follows:

P.E. = P.E. at A + Work done by forces

Since the work done by the forces is equal to the change in kinetic energy, we have:

P.E. at B = P.E. at A + K.E. at B - K.E. at A

P.E. at B = 2.4 J + 2.0 J - 0 J

P.E. at B = 4.4 J

(ii) The kinetic energy at C can be calculated as follows:

K.E. = K.E. at B + Work done by forces

Since the work done by the forces is equal to the change in potential energy, we have:

K.E. at C = K.E. at B + P.E. at C - P.E. at B

K.E. at C = 2.0 J + 0 J - 4.4 J

K.E. at C = -2.4 J

Since kinetic energy is always positive, this means that the object has gained potential energy and has lost kinetic energy.

(iii) The potential energy and kinetic energy at D cannot be determined without additional information about the work done by the forces and the change in energy between B and D.