Answer:
c)
Explanation:
When a ball is tossed upward, it rises due to the initial velocity which points upward (so it is positive if we choose the upward direction as positive), but once released, the only force (neglecting air resistance) acting on the ball is gravity.
This force is due to the mass of the Earth, and produces an acceleration in the same direction than the force, which is always downward, so in this case is negative.
As it has opposite direction to the velocity, causes the ball to slow down until it reach to a point when momentarily comes to an stop, and then changes direction falling with negative velocity, so it speeds up as it has the same sign than acceleration, that it is always present.
Answer:
a) 112.5 m
b) 15.81s
Explanation:
a)We can use the following equation of motion to calculate the velocity v of the rocket at s = 500 m at a constant acceleration of a = 2.25 m/s2



After the engine failure, the rocket is subjected to a constant deceleration of g = -10 m/s2 until it reaches its maximum height where speed is 0. Again if we use the same equation of motion we can calculate the vertical distance h traveled by the rocket after engine failure



So the maximum height that the rocket could reach is 112.5 + 500 = 612.5 m
b) Using ground as base 0 reference, we have the following equation of motion in term of time when the rocket loses its engine:



t = 15.81 or t = -6.33
Since t can only be positive we will pick t = 15.81s
Given:-
- Mass of the cart (m) = 35 kg
- Speed (consider Velocity) = 1.2 m/s
To Find: Momentum of the cart.
We know,
p = mv
where,
- p = Momentum,
- m = Mass &
- v = Velocity.
Thus,
p = (35 kg)(1.2 m/s)
→ p = 42 kg m/s (Ans.)
Conclusion:-
A. ☑️ 42 kilogram - metre per second.
Answer:
False.
Explanation:
No. Voltage does not alternate between zero and positive or negative. In non return signaling (NRZ) voltage at zero represents the 0 bit and at the positive represent the 1 bit. NRZ is one of the signal levels of uni polar Scheme in which the signal does not return to zero at the middle of it. For example 10110. That is why it named as the non return signaling.