Answer:
a)KE=878.8 J
b)W=2636.4 J
Explanation:
Given that
mass ,m = 65 kg
Initial speed ,u = 5.2 m/s
a)
We know that kinetic energy KE is given as follows
m=mass
u=velocity
Now by putting the values in the above equation we get
KE=878.8 J
b)
We know that
Work done by all forces = Change in the kinetic energy
The final velocity , v= 2 u = 2 x 5.2 m/s
v= 10.4 m/s
Now by putting the values in the above equation we get
W=2636.4 J
a)KE=878.8 J
b)W=2636.4 J
Answer:
183333 Pa
Explanation:
The weight of the football player is : 550 N ,thus the force the player exerts on the floor is 550 N
The area of blades in contact with the floor is = 30cm² = 0.003 m²
Pressure = Force / Area
Pressure = 550 / 0.003
Pressure = 183333 Pa
We must remember that the total net force equation at
constant velocity is:
<span>F – Ff = 0</span>
of
F - µN = 0
Using Newton's 2nd Law of Motion:<span>
F = m a
<span>Where,
F = net force acting on the body
m = mass of the body
a = acceleration of the body
Since the cart is moving at a constant velocity, then
acceleration is zero, hence the working equation simplifies to
F = net Force = 0
Therefore,
F - µN = 0
where
µ = coefficient of friction = 0.20
N = normal force acting on the cart = 12 N
Therefore,
F - 0.20(12) = 0
<span>
F = 2.4 N </span></span></span>
Answer:
82 degrees
Explanation:
consider your staying point to be the center of a circle. this center has the coordinates (0, 0).
the radius of the circle is the distance you walked East (14 miles).
I assume your teacher means as "angle of displacement" the angle between the East-West line going through your starting point and the direct line from your starting point to your current position.
then the 100 miles North is tan(displacement angle)×14.
as it is the same, if you first went North and then East, or the other way around. you end up at the same point, with the same coordinates.
so, again.
100 = 14×tan(angle)
tan(angle) = 100/14 = 50/7 = 7.142857...
the displacement angle is then 82 degrees.
