Answer:
they meet at distance 25 feet
Explanation:
given data
acceleration of car = 8 ft/s²
truck speed = 10 ft/s
car initial speed u = 0
truck acceleration = 0
to find out
How far from the starting point will car overtake the truck
solution
we apply here equation of motion
s = ut + 0.5 ×a×t² .............1
here s is distance and a is acceleration and t is time u is initial speed
so truck distance
s = 10t + 0.5 ×0×t²
s = 10 t ...............2
and car distance
s = 0+ 0.5 ×8×t²
s = 4×t² ..........................3
so from equation 2 and 3
10 t = 4×t²
t = 2.5 s
so both meet at distance
s = 10 (t)
s = 10 ( 2.5 ) = 25 ft
so they meet at distance 25 feet
Crystalline Solids.
In theses solids the molecules or ions are arranged in a pattern.
The smallest repeating structure is called a unit cell.Thses unit cells combine to from crystal latttices.
Salt and minerals are such an example.
Thses are also called true solids
Explanation:
This problem bothers elastic collision.
Given data
Mass m1= 25kg
Initial velocity u1= 5m/s
Final velocity v1= 1.5m/s
Mass m2= 35kg
Initial velocity u2=?
Final velocity v2 = 4.5m/s
A. To find the initial velocity of the 35kg car, let us Apply the principle of conservation of energy
m1u1+m2u2= m1v1+m2v2
25*5+ 35*u2= 25*1.5+ 35*4.5
125+35u2= 37.5+157.5
125+35u2=195
35u2= 195-125
35u2= 70
u2= 2m/s
The initial velocity is 2m/s
B. Totally not kinetic energy before impact
KE= 1/2m1u1²+ 1/2m2u2²
KE= (25*5²)/2+ (35*2²)/2
KE= 625/2 +140/2
KE= 312.5+70
KE= 382.5J
Total kinetic energy after impact
KE=1/2m1v1²+ 1/2m2v2²
KE= (25*1.5²)/2 +(35*4.5²)/2
KE= 56.25/2 +708.75/2
KE=28.125 +354.375
KE= 382.5J
We can see that energy is conserved
Kinetic energy before and after impact remains unchanged
The whole secret of things that are balanced on a pivot like this is:
The sum of all of the 'moments' is equal on both sides.
The moment of each weight is (the weight) times (its distance from the pivot).
If you add up those for each eight on one side, it has to be equal to the sum
of all the ones on the other side.
<u>2. a).</u>
The moments on the right side are: (4 x 0.15) and (1 x 0.40).
They add up to (0.60 + 0.40) = 1.00
The only moment on the left side is (C x 0.25). Both sides have to be equal.
C x 0.25 = 1.00
Divide each side by 0.25, and you have C = 4 N .
===========================================
<u>2. b).</u>
The only moment on the left side is (5 x 0.40) = 2.00
The moments on the right side are (1 x 0.20) and (D x 0.30)
They add up to (0.3D + 0.2).
Both sides have to be equal. 0.3D + 0.2 = 2.0
Subtract 0.2 from each side: 0.3D = 1.8
Divide each side by 0.3: D = 6 N