Answer:
0.82 m
Explanation:
We are given that
Weight,
=225 N
Length,l=5 m
d=1.1 m
We have to find the distance x for which person weighs 385 N walk on the overhanging part of the plank before it just begins to tip.
Half length=


When system in equilibrium then




Answer:
a structural variation in which different atoms of the same element have different numbers of neutrons
Explanation:
An isotope is an atom of an element having the same number of protons but different number of neutrons. Different isotopes are used for different purposes. Example: some are used in medicines , food irradiation, etc.
Carbon has three isotopes C 12, C 13, C 14. All three of them have 6 protons but have different numbers of neutrons.
C 12 is a common element and is abundant in nature
C 13 is less abundant than C 12
C 14 is used for dating fossils . It is radioactive
Answer
a = 3.674 m / s ^ 2
t = 3.13 s
Using the kinematic equations for the movement we have:
(1)
(2)
Where:
= initial position
= initial velocity
a = acceleration
t = time in seconds
= final speed
We know:


h = 18 m

So:
From (2) we have that: 

From (1) we have to:

Then we clear "a" to find the acceleration.

Then, the time it takes to reach this speed is:

Answer:
B
Explanation:
Use conservation of momentum: Total momentum of the system before is the same as the total momentum after the collision. Since both are moving north, the momentum of both cars is in the same direction, and the total momentum before collision is 1000kg*20m/s + 1500kg*36m/s = 74000kg-m/s.
This is the same amount of momentum after collision, and since they are locked together, their mass is added. The velocity can be found by: 74000kg-m/s ÷ 2500kg = 29.6m/s.
momentum = mass*velocity