Answer:
160N
Explanation: When 80kg mass is one group . It's reaction force acting on a ground.
Weight of the object = 80*10
= 800 N
Here we are given cofficient of static friction its 0.2. It should be smaller than 1
Friction force = Reaction * Friction Cofficient
Reaction = 800N ( Considering Vertical Equilibrium )
F = 800* 0.2
F = 160N
C. 2000 calories.
Explanation/calculation:
Specific heat capacity = calories / mass * (final temperature - initial temperature)
1 = calories / 100 * (60 - 40)
1 = calories / 100 * 20
1 * (100 * 20) = calories
1 * 2000 = calories
2000 = calories
Answer:
Explanation:
When an object goes on a circular movement, it has a centripetal acceleration that always points toward the center of the circle, it is the responsible of the change of direction in the movement of the object. and that centripetal acceleration is related with the speed in the next way:
, with v the speed, r the radius of the track that is half of the diameter (22.5 m)
B. False. beause warm air rises up in the air so first of all there is
no warm air near the ground and second of all higher the temperature
higher will be the collision of molecules so sound will travel a bit
slower than lower temperature
