Answer:
the ratio of the heat rejected to the cold reservoir for the improved engine to that for the original engine is 0.68
Explanation:
Given information
initial efficiency, η = 0.28
final efficiency, η = 0.51
ratio of the heat rejected = (1 - η)/(1 - η
)
= (1 - 0.51)/(1 - 0.28)
= 0.68
Answer:
N = 2490 N
Explanation:
Determine the upward force exerted by the horizontal platform on the box as it is lowered.
It is given that,
Mass of a box, m = 300 kg
Starting from rest at time t = 0 seconds, the box is lowered with a downward acceleration of 1.5 m/s².
It is assumed to find the upward force exerted by the horizontal platform on the box. It is given by :
mg-N=ma
So, the normal force is 2490 N.