Answer:
Option D - 0.2 s
Explanation:
We are given;
Initial velocity; u = 7 m/s
Height of table; h = 1.8m
Now,since we want to find the time the car spent in the air, we will simply use one of Newton's equation of motion.
Thus;
h = ut + ½gt²
Plugging in the relevant values, we have;
1.8 = 7t + ½(9.8)t²
4.9t² + 7t - 1.8 = 0
Using quadratic formula to find the roots of the equation gives us;
t = -1.65 or 0.22
We can't have negative t value, thus we will pick the positive one.
So, t = 0.22 s
This is approximately 0.2 s
Write an equation to calculate the force between two objects if the product of their charges is 10.0 × 10-4 C. (Note: Use the variable R for the distance between the charges.)
F = 900 ÷_________
Answer:
force = 11.33 
Explanation:
given data:
sled mass = 17.0 kg
inital velocity (U) = 4.10 m/s
elapsed time (T) 6.15 s
final velocity (V) = 0
final momentum P2 = 0
Initial momentum of sledge is


from newton second law of motion


Kgm/s^2
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Answer:
The current is reduced to half of its original value.
Explanation:
- Assuming we can apply Ohm's Law to the circuit, as the internal resistance and the load resistor are in series, we can find the current I₁ as follows:

- where Rint = r and RL = r
- Replacing these values in I₁, we have:

- When the battery ages, if the internal resistance triples, the new current can be found using Ohm's Law again:

- We can find the relationship between I₂, and I₁, dividing both sides, as follows:

- The current when the internal resistance triples, is half of the original value, when the internal resistance was r, equal to the resistance of the load.
Here we know that



now from kinematics we have

now from above all values we have



so final angular speed is -12.6 rad/s