Recent content by daniellelok

well, i think the teacher is wrong then... coz i asked her wat does vertical mean. yeah, well, the test is over anyways. mayb she just made a careless mistake on my homework...

oh...really...ok...tthx

if you draw the freebody diagram, tension up, gravity down. the cetripetal force is up, so tension must overcome gravity in order to give an upward force. so shouldn't it be tension minus gravity to get the net force?

no...it should be tan, coz i got the right answer from my equation. i just don't understand how i can get the equation on #3

y is there no gravity then?

Homework Statement this question is about a pendulum's speed. the string is 1.0m long, in which r=1m. it says the tension is twice of the bob's weight when the string is vertical, which means when its at the bottom point of the circular motion. Homework Equations since F_T should...

the equation i got is that \tan\theta=\frac{v^2}{rg}. i don't know how i got this equation, but it did give me a right answer. can u help explain it?

Homework Statement the question is to find the angle that should be banked on a highway curve. the velocity is given, which is 100km/hr and the radius is 300m Homework Equations The Attempt at a Solution i know i need to convert the units first, but then i don't know what to do...

ok tthx~~ its not in my book tho, I am not sure if the teacher will take that... thanks anyways

the given is that the mass of moon and Earth and the radius of Earth and the distance between Earth and moon

im stuck with this problem: the question asked for the gravatational force of attraction between moon and Earth while the moon's radius is not given. do i need the moon's radius? since r is the distance from the center of moon to the center of Earth (right?) and the second question of the same...