Answer:
Change in kinetic energy = 3297280 J
Explanation:
Given that,
Mass, m = 920 kg
Speed of a car, v = 92 m/s
Kinetic energy, K = 3,893,440 J
If the speed of a car, V = 36 m/s
Net kinetic energy is given by :
The change in kinetic energy = 3,893,440 - 596160
= 3297280 J
So, the change in kinetic energy of the car is 3297280 J.
I know that its not the second law. I'm almost positive its the first one. Please let me know if I'm wrong. This sentence makes no sense when you put it with the third law. So, the first law is my guess...
Answer:
b) there must be a component of force parallel to the motion of the object.
Explanation:
We know that work done on a body by an external force is calculated by the formula given below:
W = F.d = Fd Cos θ
where,
W = Work Done by the force on the body
F = Magnitude of force
d = displacement of the body
θ = The angle between the direction of motion of the body and the force applied
It is clear from the formula of the work done, that "F Cosθ" represents the component of the force, that is acting in the direction of motion of the object or parallel to the direction of motion of the object. So, if there is no component of force parallel to motion of object, then this factor will become zero. As a result, the work done will also be zero.
Therefore, the correct option will be:
b) <u>there must be a component of force parallel to the motion of object.</u>
Given E=2050 N/C
charge of an electron = 1.6×10^-19 C
USING E = F/Q , electric field = force ÷ charge
2050 = F ÷ (1.6×10^-19)....
make F subject of formula and get the answer
