Answer:
For every action, there is an equal and opposite reaction.
Explanation:
Physics helps alot lol
Answer:
mu = 0.56
Explanation:
The friction force is calculated by taking into account the deceleration of the car in 25m. This can be calculated by using the following formula:

v: final speed = 0m/s (the car stops)
v_o: initial speed in the interval of interest = 60km/h
= 60(1000m)/(3600s) = 16.66m/s
x: distance = 25m
BY doing a the subject of the formula and replace the values of v, v_o and x you obtain:

with this value of a you calculate the friction force that makes this deceleration over the car. By using the Newton second's Law you obtain:

Furthermore, you use the relation between the friction force and the friction coefficient:

hence, the friction coefficient is 0.56
Answer:
8.61 min
Explanation:
original mass= 12.65
first half life = 12.65/2 = 6.325
second half life = 6.325/2 = 3.1625
Note : 3.1625 is the closest to the value (3.115) given so we work with it
total time for decay =17.22
therefore two decays = 17.22/2= 8.61
Answer:
The speed of the ball is 9.07 m/s.
Explanation:
Given that,
Mass of the lead ball, m = 55 kg
Height of the tower, h = 55 m
We need to find the speed of the ball it has traveled 4.20 m downward, x = 4.2 meters
The initial speed of the ball will be 0 as it was at rest initially. Let v is the speed of the ball after it has traveled 4.20 m downward. It is a case of equation of motion such that :


Here, a = g

v = 9.07 m/s
So, the speed of the ball is 9.07 m/s. Therefore, this is the required solution of given condition.
A star’s death also depends on its mass. The most massive stars
quickly exhaust their fuel supply and explode in core-collapse
supernovae, some of the most energetic explosions in the universe. A
supernova’s radiation can easily (if only briefly) outshine the rest of
its host galaxy. The remnant stellar core will form a neutron star
or a black hole, depending on how much mass remains. If the core
contains between 1.44 and 3 solar masses, that mass will crush into a
volume just 10 to 15 miles wide before a quantum mechanical effect known
as neutron degeneracy pressure prevents total collapse. The
exact upper limit on a neutron star mass isn’t known, but around 3 solar
masses, not even neutron degeneracy pressure can combat gravity’s
inward crush, and the core collapses to form a black hole.