Answer:
Difference is given below.
Explanation:
The main difference between beneficial and harmful friction is that beneficial friction is necessary for performing different activities while on the other hand, harmful effect of friction is destroy different parts of products and machines. examples of beneficial friction are walking, holding things, rubbing hands to produce heat, running etc whereas examples of harmful friction are destruction of sole, slipping, tearing of machine's part, Wet roads and Mudslides etc.
In uniform circular motion, the factor that remains constant is.............
Answer:
When a body is in uniform circular motion, its speed remains constant but its velocity, angular acceleration, angular velocity changes due to change in its direction.
An airplane is traveling at an altitude of 15,490 meters. A box of supplies is dropped from its cargo hold. What is the cargo's velocity when it hits the ground? (Show your work and do not forget units)
Answer :
556.59 m/s.
Explanation:
Given that,
An airplane is traveling at an altitude of 15,490 meters.
A box of supplies is dropped from its cargo hold. We need to find the velocity of cargo when it hits the ground.
The initial velocity of the box is 0 as it as at rest. Let v is the velocity of cargo when it hits the ground. We can find it using third equation of motion as follows :
[tex]v^2-u^2=2as[/tex]
Put u = 0 and a = g
[tex]v^2=2gs\\\\v=\sqrt{2gs} \\\\v=\sqrt{2\times 10\times 15490 } \\\\v=556.59\ m/s[/tex]
So, when it hits the ground its velocity is 556.59 m/s.