Answer:
Options A, B, and C are all possible.
Explanation:
We know that the instantaneous velocity of the dog at 3:14PM is possitive to toward the flowers. But what about the acceleration to toward the flowers?
If the dog is decreasing speed at 3:14PM, it means that acceleration is negative toward the flowers, hence (since F=ma) the net force points away from the flowers.
If the dog is increasing speed at 3:14PM, it means that acceleration is positive toward the flowers, hence (since F=ma) the net force points toward the flowers.
If the dog is not increasing nor decreasing speed at 3:14PM, it means that acceleration is 0, hence (since F=ma) the net force is null and it does not point neighter to toward the flowers nor away from the flowers. This happens when the forces acting on the dog are equal to both sides.
Answer:
Part A: 16.1 V
Part B: 20.5 V
Part C: 21.5%
Explanation:
The voltmeter is in parallel with the 4.5-kΩ resistor and the combination is in series with the 6.5-kΩ resistor. The equivalent resistance of the parallel combination is given as
Part A
The voltmeter reading is the potential difference across the parallel combination. This is found by using the voltage-divider rule.
Part B
Without the voltmeter, the potential difference across the 4.5-kΩ resistor is found using the same rule as above:
Part C
The error in % is given by
Explanation:
I assume the acceleration calculated in part (b) is the 3.33 m/s² from your other question.
Use Newton's second law to find the total force:
F = ma
F = (60,000 kg) (3.33 m/s²)
F = 200,000 N
Since there are 2 engines, the thrust from each is half of this:
F = 100,000 N
In reality, there are forces other than thrust. There are also drag forces (rolling friction and air resistance).
From Newton's second law, if we increase the mass and keep the force the same, the acceleration decreases. So it would take longer to reach the take-off speed.
Answer:
6J
Explanation:
Given parameters:
Mass of fish = 1kg
Velocity = 12m/s
Unknown:
Change in kinetic energy = ?
Solution:
Kinetic energy is the energy due to the motion of a body. It is mathematically given as:
K.E = m v²
Now, insert the parameters and solve;
K.E = x 1 x 12 = 6J
The change in kinetic energy is 6J
a) 6.25 rad/s
The law of conservation of angular momentum states that the angular momentum must be conserved.
The angular momentum is given by:
where
I is the moment of inertia
is the angular speed
Since the angular momentum must be conserved, we can write
where we have
is the initial moment of inertia
is the initial angular speed
is the final moment of inertia
is the final angular speed
Solving for , we find
b) 28.1 J and 35.2 J
The rotational kinetic energy is given by
where
I is the moment of inertia
is the angular speed
Applying the formula, we have:
- Initial kinetic energy:
- Final kinetic energy: