Answer:
Explanation:
a )
initial velocity u = 45 m/s
acceleration a = - 5 m/s²
final velocity v = 0
v = u - at
0 = 45 - 5 t
t = 9 s
b )
s = ut - 1/2 at²
= 45 x 9 - .5 x5x 9²
405 - 202.5
202.5 m
2 )
a )
s = ut + 1/2 a t²
u = 0
s = 1/2 at²
= .5 x 9.54 x 6.5²
= 201.5 m
b )
v = u + at
= 0 + 9.54 x 6.5
= 62.01 m / s
3
a )
acceleration = (v - u) / t
= (34 - 42) / 2.4
= - 3.33 m /s²
b )
v² = u² - 2 a s
34² = 42² - 2 x 3.33² s
s = 27.41 m
c )
Average velocity
Total displacement / time
= 27.41 / 2.4
= 11.42 m /s
4 )
a )
v = u + at
v = 0 + 3 x 4
= 12 m /s
b )
s = ut + 1/2 a t²
= o + .5 x 3 x 4²
= 24 m
Is a physical change because only the state of the matter has changed.
Physical changes can often be reversed. Allowing the water to evaporate will return the salt to a solid state.
It has not combined with the water to cause an irreversible chemical reaction.
Answer:
horizontal structural member that supports a floor. Beams are typically wood, cold formed metal framing or steel.
Joists
Horizontal timbers, beams or bars supporting a floor.
Answer:A market economy is a system where the laws of supply and those of demand direct the production of goods and services. 1 Supply includes natural resources, capital, and labor. Demand includes purchases by consumers, businesses, and the government. Businesses sell their wares at the highest price consumers will pay.
Explanation:
Answer:
The potential energy of the rock = 10.5 kN
Explanation:
Mass of rock = 25 kg
Acceleration due to gravity = 10 m/s²
Height = 42 m
Potential energy, PE = mgh, where m is the mass, g is acceleration due to gravity and h is the height.
PE = 25 x 10 x 42 = 10500 N = 10.5 kN
The potential energy of the rock = 10.5 kN
