Answer:
(a) = 0 N
(b) = 2.4 N
Explanation:
given
box of banana weight = 40.0 N
coefficient of static friction μ = 0.40
coefficient of kinetic friction = 0.20
a). when no horizontal force is applied .
according to Newton 's third law of motion If there is no force applied to the box,so the frictional force exerted is 0 N
b) magnitude of friction force
box and the box is initially at rest
friction force =.Static friction coefficient × weight of the box
friction force = 0.40 × 6
friction force = 2.4 N
<span>The lowest point in Death Valley is 85 m below sea level. The summit of nearby Mt. Whitney has an elevation of 4420 m. </span>
The density of the fluid is 776.3 
<u>Explanation:</u>
Buoyant force is the upward pushing force whenever an object is trying to get immersed in fluid. So this is the force given by the fluid on the object which is trying to get immersed. The buoyant force is found to be directly proportional to the product of density of the object, volume of the object. And here the acceleration due to gravity will be acting as proportionality constant.

As, buoyant force is given as 671 N and volume is 0.0882
and acceleration is known as 9.8 m/
. Then density is

Thus,

Density is 776.3 kg
.