Answer:
4) True. The change of direction needs an unbalanced force
Explanation:
Let us propose the resolution of the problem using Newton's second law.
F = m a
As the car is spinning the acceleration is centripetal
a = v2.r
F = m v2 / r
We can see that as the velocity of a vector even if its module does not change, the change of direction requires an external force.
Now we can analyze the statement if they are true or false
1) and 3) False, even when the speed changes, the direction changes
2) False with the speed change can be determined
4) True. The change of direction needs an unbalanced force
5) False are different things. the direction is where it is going and the speed is the magnitude of the vector
Explanation:
voltage = current × resistance
5.
12 V = 4.2 A × resistance
resistance = 12 V / 4.2 A = 2.857142857... Ohm
FYI :
4.2 A would be a lot for a small electronic device like a CD player. that would be 12×4.2 = 50.4 Watt, and the CD player would get really hot.
6.
120 V = current × 12 Ohm
current = 120 V / 12 Ohm = 10 A
Answer:
Examples of Newton's third law of motion are ubiquitous in everyday life. For example, when you jump, your legs apply a force to the ground, and the ground applies and equal and opposite reaction force that propels you into the air. Engineers apply Newton's third law when designing rockets and other projectile devices.
It only occurs when there is an electric current
Frequency of a sound wave is commonly referred to as pitch. That is the specialized name for frequency of a sound wave.
Just remember it as pitch.