Acceleration is the increase in the rate of speed so if its acceleration is decreasing then I guess use negative.
hope this helps
v = 18cos48 m/s
So time = distance/speed
= 28/18cos48
= 2.3247413
Resolving vertically, now use s = ut + (0.5)a(t^2)
Where s is the unknown distance (the height above the GROUND)
u is initial (vertical) speed = 18sin48
a = -9.8 m/s (negative since we take upwards as positive)
t = 2.3247... (what we found previously)
Putting the numbers into the formula gives 4.616126809
Take away the height of the goalpost (3.05) = 1.566126809
= 1.57m above the crossbar.
hope this helps :)
Answer:
Explanation:
First, the box goes from position x=0 to x=x1, so, the work made by the friction is calculated as:
where is the force of friction, the displacement, m the mass, V is the speed in rest and the initial speed.
V is equal to zero, so:
it means that the force of friction is equal to:
On the other hand, when the box goes from position x=x1 to x=x2, the work-energy theorem said that:
Where is the work done by the person.
Then, solving for :
Finally, replacing by , we get:
Answer:
Inertia
Explanation:
People can float in space since there is no gravity. Pretty Simple? The reason why thingsvlike planets and stars don't move is due to Inertia, which keeps the things in line in the solar system.
This is
an example of point source pollution. <span>Pollutants from point
sources come from a specific and identifiable location. Pollution from point
sources has become a minor problem for the environment and human health because
point sources are more identified and regulated today than in the past. However,
large volumes of rain, inadequate treatment, system failures and other
circumstances can still make the point source a potential hazard to the
environment and human health.</span>