Verifica sul moto circolare uniforme e la gravità. La verifica può essere utilizzata nelle classi in cui sono attivi dei percorsi CLIL di Fisica in lingua inglese.
Circular Motion and Gravity
1. In order for an object to be travelling in a circle, there must be a _______________ force acting on it, and that force must always point ___________________.
2. When an object is moving in a circle, the object’s velocity points _______________ and its acceleration points _____________.
3. What is the equation for centripetal force?
4. If the velocity of an object doubles but the radius stays the same, how must the centripetal force change to keep it in the circle?
5. A ball is attached to a string and spun around in a circle. If it is spun with a constant force, how will the speed change if the ball is replaced with one with half the mass?
6. Recall the water in the cup lab. The radius of the string was 80cm, and the mass of the cup was 150g. The team timed that one revolution took 0.9s.
a. Determine the circumference of the circular path that the cup went around.
b. Determine the velocity of the cup.
c. Determine the centripetal acceleration of the cup.
d. Determine the centripetal force on the cup.
7. Recall the airplane lab.
a. What force (or component of a force) provided the centripetal force that kept the airplane in a circle?
b. Explain the two ways that we calculated centripetal force using the data we collected in the lab.
8. If the force of gravity between two objects has been reduced by 1/4 which could be true?
a. Mass was increased 4 times
b. Mass was decreased 2 times
c. Distance was increased 4 times
d. Distance was doubled
9. The force of gravity on Jupiter is a little more than 2 times the gravitational force on Earth. If an object has a mass of 50 kg and a weight of 490 N on Earth, what would be the object’s approximate mass and weight on Jupiter?
a. 50 kg and 490 N
b. 100 kg and 490 N
c. 50 kg and 980 N
d. 100 kg and 980 N
10. You are travelling in a circle at a constant speed.
a. Is your velocity constant?
b. Are you accelerating? If yes, in what direction?
11. A cup of water resting on a cardboard swing is spun around in a vertical circle, like you did in the lab. Hint- the string is not touching the cup- the cardboard it is resting on is applying the force.
a. Draw a force diagram showing the force(s) on the cup at the top of the circle.
b. Draw a force diagram showing the force(s) on the cup at the bottom of the circle.
c. If the mass of the cup and water is 0.06 kg and has a constant speed of 2.5 m/s and the string has a length of 0.8m, solve for the centripetal force.