Answer:
the acceleration of the elevator is increasing
Explanation:
For this exercise we propose the solution using Newton's second law
F -W = m a
F = m (g + a)
If the net force increases, it implies that the acceleration of the elevator is increasing, since the acceleration of gravity is constant as the ascent is accelerating.
The correct answer among the choices given is the last option. Cora wrapping the copper wire with a thick plastic coating keeps a current from passing out a wire. The plastic wire here serves as an insulator. An insulator is a material that prevents electricity or current to flow out the circuit. In order to lessen the loss of energy.
HOPE THIS HELPS!
Answer:
22m/s
Explanation:
Mass, m=60 kg
Force constant, k=1300N/m
Restoring force, Fx=6500 N
Average friction force, f=50 N
Length of barrel, l=5m
y=2.5 m
Initial velocity, u=0
Substitute the values
m
Work done due to friction force
We have 
Substitute the values
Initial kinetic energy, Ki=0
Initial gravitational energy, 
\
Initial elastic potential energy
Final elastic energy,
Final kinetic energy, 
Final gravitational energy, 
Final gravitational energy, 
Using work-energy theorem
Substitute the values
Your potential energy at the top of the hill was (mass) x (gravity) x (height) .
Your kinetic energy at the bottom of the hill is (1/2) x (mass) x (speed)² .
If there was no loss of energy on the way down, then your kinetic energy
at the bottom will be equal to your potential energy at the top.
(1/2) x (mass) x (speed)² = (mass) x (gravity) x (height)
Divide each side by 'mass' :
(1/2) x (speed)² = (gravity) x (height) . . . The answer we get
will be the same for every skater, fat or skinny, heavy or light.
The skater's mass doesn't appear in the equation any more.
Multiply each side by 2 :
(speed)² = 2 x (gravity) x (height)
Take the square root of each side:
<u>Speed at the bottom = square root of(2 x gravity x height of the hill)</u>
We could go one step further, since we know the acceleration of gravity on Earth:
Speed at the bottom = 4.43 x square root of (height of the hill)
This is interesting, because it says that a hill twice as high won't give you
twice the speed at the bottom. The final speed is only proportional to the
<em>square root </em>of the height, so in order to double your speed, you need to
find a hill that's <em>4 times</em> as high.
Object A has the larger speed because speed is not a vector quantity, it is scalar. This means that directionality, or in this case the sign of the velocity, doesn’t matter.
Speed = |velocity|
Object a speed =|-10|=10 m/s
Object b speed =|5|=5 m/s
Object a is the answer.
