Answer:
The one with highest velocity
Explanation:
The momentum of an object is given by
where
m is the mass of the car
v is the velocity of the car
In this problem, we have two identical cars: identical means they have same mass, so
The momentum of car 1 is
while the momentum of car 2 is
By comparing the two expressions, we see that the car with greatest momentum is the one with highest velocity, since the mass is the same.
The correct answer to the question is: 78.4 N.
CALCULATION:
As per the question, the mass of the object is given as m = 8 Kg.
We are asked to calculate the force of 8 Kg object pushing up from the table.
The force pushing up from the table is nothing else than the normal reaction.
The normal reaction of the object is equal to the weight of the object as the object is simply resting on the table.
Hence, normal reaction = Weight
= mg
= 8 × 9.8 N.
= 78.4 N.
Here, g is known as acceleration due to gravity.
Hence, the force of the object pushing up from the table is 78.4 N.
Answer:
B. 16 kJ
Explanation:
Energy = VIt.............. Equation 1
Where V = Voltage, I = Current, t = time
Given: V = 5.0 V, I = 1.5 A, t = 1 h = 3600 s.
Substitute these values into equation 2
E = 5.0(1.5)(3600)
E = 27000 J
E = 27 kJ.
Amount of energy left = 43 kJ - 27 kJ
Amount of energy left = 16 kJ.
Hence the right option is B. 16 kJ
