1. You pull on a 5 kg object with a force of 30 N. The frictional force acting on the same object is 10 N. What is the object檚 acceleration?
2. A car traveling on Route 1 hits a bug. The sudden change in momentum for the bug splats in on the windshield. How does the change in momentum for the car compare to the bug?Two problems I am struggling with?
(1)The 10N frictional force acts opposite the force that you are applying, so the net force that is available to accelerate the object is 30 - 10 = 20N. Since the object has a 5 kg mass, the acceleration a = F/m (force/mass) = 20/5 = 4 meters per sec^2.
(2) If we assume that the bug is standing still (i.e. zero momentum) when the car hits it, and that the car was coasting at the time, then the velocity of the car will decrease by a fraction M(bug)/[M(car) + M(bug)] in order to conserve momentum. If the bug was moving at the time, momentum is still conserved: the momentum of the bug plus the momentum of the car is constant.Two problems I am struggling with?
1. net force is 30-10 because they're acting in opposite directions, so 20N. F=ma so, a=F/m, so a=20/5=4m/s2
2. the car's momentum would change a very tiny fraction... the bugs momentum changes hugelyTwo problems I am struggling with?
1N = 1kg m /s2 (second squared not times 2)
F=M A
(30-10) kg m /s2 = 5 kg A
A= 4 m/s2
question two, depends on the mass of the bug.Two problems I am struggling with?
The car weighs roughly 3200 lbs or 1500 kg. Lets say it was a bee which weighs about 100mg which represents 1/10,000 kg and that the bee was travelling at a speed of 15mph. Then the resulting change in speed of the car is 1/1000,000 mph or a millionth of an mph.
