Answer:
58.27 N
Explanation:
the data we have is:
mass: 
coefficient of friction: 
and we also know the acceleration of gravity is 
We need to do an analysis of horizontal and vertical forces acting on the object:
-------
Vertically the forces acting on the object:
- Normal force
(acting up from the object)
- weight:
(acting down from)
so the sum of forces in the vertical axis "y" are:
from Newton's second Law we know that 
, so:
and since the object is not accelerating in the vertical direction (the movement is only horizontal) 
, and:
-----------
now let's analyze the horizontal forces
- frictional force:
and since 
--> 
- force to move the object:
and the two forces just mentioned must be opposite, thus the sum of forces in the "x" axis is:
and we are told that the crate moves at a steady speed, thus there is no acceleration: 
and we get:
substituting known values:
The density of seawater plays a vital role in causing ocean currents and circulating heat because of the fact that dense water sinks below less dense. long story short, seawater is the problem because its denser than pure water.
Speed= distance/time
Speed= 150000m/7200s=20.83m/s(cor.to.2d.p.)
The lithosphere because it includes the outer region of the earth including the crust and outer mantle
Answer: 2812500 joules
Explanation:
Mass of car = 1500kg
Velocity of car = 75mph
Kinetic energy = ?
Recall that kinetic energy is the energy possessed by a moving object, and it depends on its mass M and velocity, V
Thus, Kinetic energy = 1/2 x mv^2
= 1/2 x 1000kg x (75mph)^2
= 0.5 x 1000kg x (75mph)^2
= 500 x 5625
= 2812500 joules
Thus, the car travels with a kinetic energy of 2812500 joules
