Answer:
Choice a. 1 kg, assuming that all other forces on the object (if any) are balanced.
Explanation:
By Newton's Second Law,
,
where
is the acceleration of the object in
,
is the net force on the object in Newtons, and
is the mass of the object in kilograms.
As a result,
.
Assume that all other forces on this object are balanced. The net force on the object will be
. The net force is constant. Acceleration should also be constant and the same as the average acceleration in the two seconds.
<h3>What is the
average acceleration of this object?</h3>
.
.
<h3>Apply Newton's Second Law to find the mass of the object.</h3>
.
Answer: 17.68 s
Explanation:
This problem is a good example of Vertical motion, where the main equation for this situation is:
(1)
Where:
is the height of the ball when it hits the ground
is the initial height of the ball
is the initial velocity of the ball
is the time when the ball strikes the ground
is the acceleration due to gravity
Having this clear, let's find
from (1):
(2)
Rewritting (2):
(3)
This is a quadratic equation (also called equation of the second degree) of the form
, which can be solved with the following formula:
(4)
Where:



Substituting the known values:
(5)
Solving (5) we find the positive result is:

Answer:

Explanation:
The work done on a particle by external forces is defined as:

According to Newton's second law
. Thus:

Acceleration is defined as the derivative of the speed with respect to time:

Speed is defined as the derivative of the position with respect to time:

Kinetic energy is defined as
:

I'd say move faster, unless it's asking something else.
Explanation:
<u>Formula:</u>

<u>d = distance given</u>
<u>t</u><u> </u><u>=</u><u> </u><u>the amount of time </u><u>given</u>
<u>Substitute the given values into the formula for velocity</u><u>:</u>

velocity is shortened for v.
8 (distance) divided by 4 (time) equals the velocity.
<u>Solve:</u>

The velocity of the toy car equals: B. 2 m/s.