Impulse = Force * times and also Impulse = change in momentum.
Given that the mass does not change, change if momentum = mass * (final velocity - initial velocity)
Given that you know mass and initial velocity (which is the velicity before the cart hits the wall) you need the final velocity (which is the velocity after the cart hits the wall).
Answer: the velocity of the cart after it hits the wall.
Answer:
The two objects are traveling at the same speed.
Explanation:
Neglecting air resistance, an object that is thrown up from the top of a tall building has the same speed as the second object thrown down from the top of the same tall building since the initial speed is the same.
The object thrown up is not traveling faster neither is the object thrown down traveling faster.
Therefore, the two objects will have the same speed when they hit the ground but their time of landing might be different.
Answer:
A) B = 5.4 10⁻⁵ T, B) the positive side of the bar is to the West
Explanation:
A) For this exercise we must use the expression of Faraday's law for a moving body
fem = 
fem =
- d (B l y) / dt = - B lv
B = 
we calculate
B = - 7.9 10⁻⁴ /(0.73 20)
B = 5.4 10⁻⁵ T
B) to determine which side of the bar is positive, we must use the right hand rule
the thumb points in the direction of the rod movement to the south, the magnetic field points in the horizontal direction and the rod is in the east-west direction.
Therefore the force points in the direction perpendicular to the velocity and the magnetic field is in the east direction; therefore the positive side of the bar is to the West