1. Why is the direction of free fall acceleration sometimes negative?
1 answer:
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Answer:
A) If the paintball stops completely the magnitude of the change in the paintball’s momentum is
B) If the paintball bounces off its target and afterward moves in the opposite direction with the same speed, the change in the paintball’s momentum is
C) A paintball bouncing off your skin in the opposite direction with the same speed hurts more than a paintball exploding upon your skin because of the strength exerted is twice than if it explodes.
Explanation:
Hi
A) We use the formula of momentum , so we have
B) We use the same formula above, then due we have a change of direction at the same speed, therefore the change in the momentum is the double so
.
C) The average strength of the force an object exerts during impact is determined by the amount the object’s momentum changes. therefore
, as we don't have any data about the impact time but we know momentum is twice, time does no matter and strength is twice too.
From laws of motion:
Where S is the distance/displacement (as you would call it) which is unknown
v = final velocity which is 0m/s (this is because the car stops)
u = initial velocity which is 36m/s (from the data given)
t = time taken for the distance to be covered and it is 6s
Substitute the values, hence:
But this is merely the distance he travelled in the 6 seconds he was trying to stop the car.
Therefore, the distance between the car and the cows = 160-108
Distance = 52m
Where S is the distance/displacement (as you would call it) which is unknown
v = final velocity which is 0m/s (this is because the car stops)
u = initial velocity which is 36m/s (from the data given)
t = time taken for the distance to be covered and it is 6s
Substitute the values, hence:
But this is merely the distance he travelled in the 6 seconds he was trying to stop the car.
Therefore, the distance between the car and the cows = 160-108
Distance = 52m