Answer:
When the ball is held motionless above the floor, the ball possesses only GPE energy.If the ball is dropped, its GPE energy decreases as it falls.If the ball is dropped, its KE energy increases as it falls.
Explanation:
If the ball is held motionless, then its kinetic energy is equal to zero, since kinetic energy depends on the velocity. And the ball is held above the ground, which means it possesses gravitational potential energy.
If the ball is dropped, its height will decrease, therefore its gravitational potential energy will decrease. Along the way, the ball will be in free fall, and therefore its velocity will increase, hence its kinetic energy.

Answer:
The linear momentum of a particle with mass m moving with velocity v is defined as
p = mv (7.1)
Linear momentum is a vector . When giving the linear momentum of a particle you must
specify its magnitude and direction. We can see from the definition that its units must be
kg·m
s
. Oddly enough, this combination of SI units does not have a commonly–used named so
we leave it as kg·m
s
!
The momentum of a particle is related to the net force on that particle in a simple way;
since the mass of a particle remains constant, if we take the time derivative of a particle’s
momentum we find
dp
dt = m
dv
dt = ma = Fnet
so that
Fnet =
dp
dt (7.2)
Answer: Use less water
only turn on lights when needed
electrical cars
less gas usage
Explanation:
Answer:
.409 N
Explanation:
For this to balance, the moments around the fulcrum must sum to zero.
On the left you have .21 ( is that down? I will assume it is)
Counterclockwise moments :
.21 * 40 + 1.0 * 20
Clockwise moments :
.5 * 20 + F * 45
these moments must equal each other
.21*40 + 1 *20 = .5 * 20 + F * 45
F = .409 N
Answer:
3 years
Explanation:
Find the circumference of each orbit in AU.
2xπx1=6.283185307
2xπx3=18.84955592
Divide them.
18.84955592/6.283185307=3
3 years