Units and Motion
True or false: An object moving in a circle at a constant speed is not accelerating
False
__________ force is the reaction force that occurs when an object is pushing against a surface.
Normal
True or false: Momentum is conserved in an inelastic collision?
True
__________ waves do not require a medium to travel through because they can also act as particles.
Electromagnetic (light)
How does a neutral atom become positively charged (in terms of gaining/losing protons/electrons)?
It loses electrons
A car with an initial velocity of 35m/s is braking (accelerating) at a rate of -5m/s2. How long will it take for the car to come to a complete stop?
t = 7s
A 10kg block is being pushed to the right across a flat table by a force of 20N. A frictional force of 6N is resisting it's motion. What is the normal force acting on the block?
FN = 98N
A car's engine is providing a 3000N force to the right. There is also a frictional force of 1000N to the left. How much work does the engine do to move the car 50m to the right?
W = 150,000J
What is the wavelength of a 25Hz wave that is moving at 5m/s?
Wavelenght = 0.2m
Draw the charge distribution on a neutral electroscope when a positively charged rod is brought near (but not touching) the top.
(see white board)
Convert 3m2 to cm2
30,000cm2 or 3*104cm2
A 10kg block is being pushed to the right across a flat table by a force of 20N. A frictional force of 6N is resisting it's motion. What is the net force acting on the block?
Fnet = 14N to the right
A 5kg ball is held 2m above the ground. What is the ball's potential energy?
PE = 98J
Fill in the blanks with: air, water, glass, or a vacuum.
Sound waves travel fastest in ________ and light waves travel fastest in ________.
Glass ; A Vacuum
Draw the electric field between one positive and one negative source charge.
(see white boards)
A ball is dropped from a 60m tall cliff. How long will it take to hit the ground?
t = 3.5s
A car of mass 1450 kg is traveling down the highway at 25 m/s. The coefficient of kinetic friction between the car and the highway is 0.15. What is the force of friction acting on the car?
Fk = 2131.5N
A 5kg ball is dropped from 2m above the ground. What is the ball's kinetic energy right before it hits the ground?
KE = 98J
Fill in the blacks with some combination of: red, blue, green, white, and black.
Blue light shining on a red filter will block _______ and transmit __________.
Blue ; Black
A charge of +15 µC and another of -35 µC are held apart at a distance of 0.75 m. What is the electric force between the two charges?
F = -8.4N
A ball is thrown from a 60m tall cliff with a horizontal velocity of 8m/s. How far away (horizontally) from the base of the cliff will the ball land?
dx = 28
Draw a FBD of a block that at rest on a 45o inclined ramp. Make sure to include all forces acting on the block (you don't need components)
(see white board)
A 3kg ball is thrown from a 60m tall cliff with a horizontal velocity of 8m/s. What is the ball's total mechanical energy? Hint: Find potential and kinetic energy.
ME = 1860J
A 6th harmonic standing sound wave is contained in a 1.2m long hollow PVC pipe that is open at both ends. What is the wavelength of that wave?
Wavelength = 0.4m
A +35 µC plate is used to make a positively-charged ball hover 1m above the plate. If the weight force (Fw) of the charged ball is 10 N, what is the charge of the ball?
q = 31.7 µC