<h2>
Time taken is 0.632 seconds</h2>
Explanation:
Impulse momentum theorem is change in momentum is impulse.
Change in momentum = Impulse
Final momentum - Initial momentum = Impulse
Mass x Final velocity - Mass x Initial Velocity = Force x Time
Mass x Final velocity - Mass x Initial Velocity =Mass x Acceleration x Time
Final velocity - Initial Velocity = Acceleration x Time
Final velocity = 9.9 m/s
Initial Velocity = 3.7 m/s
Acceleration = 9.81 m/s²
Substituting
9.9 - 3.7 = 9.81 x Time
Time = 0.632 seconds
Time taken is 0.632 seconds
Answer:
-0.55m/s
Explanation:
Given that: For the boy
Weight = 745N
Velocity = +0.35 m/s
Mass of the boy = ?
g = 9.81m/s^2
W = mg
745 = m×9.81
m = 75.94kg
For the girl
Given that:
Weight = 477 N
g = 9.81m/s^2
m = ?
W = mg
477 = m×9.81m/s^2
m = 48.62kg
To solve for the v of the girl, the two has to add up
48.62kg×v + 75.94kg×+0.35 m/s = 0
48.62v + 26.579 = 0
48.62v = - 26.579
v = -26.579/48.62
v = -0.5466
v = -0.55m/s
Hence, the velocity of the girl is -0.55m/s.
The negative sign is as a result of the two of them moving is opposite direction.
Answer:
D. crystalline solid that conducts current under certain conditions
Explanation:
Semiconductors are crystalline solids that has the ability to conduct electrical currents but on certain conditions e.g heat. The conduction of semiconductors is less than that of conductors (metals) but more than insulators (nonmetals), hence, they are said to be intermediates of conductors and insulators in terms of electrical conductivity.
Examples of semiconductors are silicon, boron, carbon, germanium, arsenic etc.
