Answer:
The running horizontal speed should be larger than 1.29 m/s.
Explanation:
In order for the swimmer to just miss the bone-breaking ledge, her horizontal speed must be
in which we need to know how long we she be diving through the air. To determine that, recall the formula for the distance made by an object with acceleration (in this case it is the gravitational acceleration) with no initial (vertical) velocity:
from which it follows that (for non-negative t)
This result can be used in the initial inequality:
The diving lady better gets a speed larger than 1.29 m/s to avoid landing on the ledge.
When ANY pendulum bob reaches the top of its swing,
it stops momentarily and then begins to drop. At the instant
when it stops, its kinetic energy is zero.
Answer:
Explanation:
<u>Mechanical Force</u>
According to the second Newton's law, the net force F exerted by an external agent on an object of mass m is:
F = m.a
Where a is the acceleration of the object.
Assume we apply some given force F to an object of m1=1 Kg that produces an acceleration 
, then:
F = m1.a1
The same force F is now applied to a second object m2=4 Kg that produces an acceleration a2, then:
F = m2.a2
Dividing both equations:
Solving for a2:
Substituting values:
Answer:
B) Angular velocity
Explanation:
The equivalent of Newton's second law for the rotational motions can be written as:
where
is the net torque applied to the object
I is the moment of inertia
is the angular acceleration
From the formula we see that when a constant net torque is applied, then the object also has a constant angular acceleration, .
But we also know that
where 
is the angular velocity: so, a constant angular acceleration means that the angular velocity of the object is changing, so the correct answer is
B) Angular velocity
(moment of inertia and center of gravity do not change since they only depend on the mass and the geometry/shape of the object, which do not change)
