Comp 1
Comp 2
Chapter 5
Equations
Calculations
100
How many sig figs are in the following measurements? 0.04530 L, 12.3450 kg, 1 m is equal to 100 cm, 450 mm
4, 6, unlimited, 2
100
What is inertia?
The tendency of an object to resist changes in its motion
100
What does gravitational potential energy depend on?
The object's mass, height and gravity
100
What is the equation used to calculate an object's velocity? What are the variables & units?
v = d/t, v is velocity (m/s), d is displacement (m), t is time (s)
100
David Rudisha of Kenya ran the 800 m run in a time of 101 s. How fast did he run this race? (use 3 sig figs)
7.92 m/s
200
Which number is "uncertain" in the measurement of 1.357 m?
7
200
Convert 102 km/hr to m/s
28.3 m/s
200
What does kinetic energy depend on?
Mass & velocity
200
What is the equation for Newton's 2nd Law of Motion? What are the variables and units?
F=ma; F is force (N), m is mass (kg), a is acceleration (m/s2)
200
How much force is needed to accelerate a water skier with a mass of 72 kg by 1.2 m/s2?
86 N
300
What is the difference between accuracy and precision?
Accuracy is how close a measurement is to a true/accepted value and precision is how close measurements are to one another.
300
A 26.7 N force is applied at 33 degrees north of east. What are the x and y components?
x = 22N, y = 15 N
300
What is the difference between KE, PEg, and PEelastic?
KE is the energy of motion, PEg is the energy associated with position, and PEelastic is the energy stored in elastic materials.
300
What are the equations to calculate work? What are the variables & units?
W=Fd or W=Fd(cos@); W is work (J), F is force (N), d is distance (m); @ is theta (the angle)
300
Calculate the work done when a 22 N force pushes a cart a distance of 3.35 m.
74 J
400
What are the equations to calculate absolute and relative error?
Abs = |accepted - experimental|; Relative = (abs/acc)*100
400
A lab group of students measures the length of a textbook. The group's average was 19.5 cm. If the accepted value of the textbook was 21.2 cm, calculate the group's absolute and relative error.
absolute = 1.70 cm; relative = 8.02%
400
What does the k value represent in the elastic potential energy equation? What does a small k value mean?
The spring constant. The smaller the k value, the more flexible the spring is.
400
What is the equation to calculate the kinetic energy? What are the variables & units?
KE = 0.5(m)v^2; KE is kinetic energy (J), m is mass (kg), v is speed (m/s)
400
What is the kinetic energy of a roller coaster cart that has a mass of 505 kg if it is moving at a speed of 20.2 m/s?
103,000 J
500
A person walks 42 m north, then walks 24 m east. What is the person's resultant displacement?
48 m, 30 degrees east of north
500
What are the units for acceleration, displacement, energy, force, mass, power, time, weight, work, velocity?
m/s2, m, J, N, kg, W (or hp), s, N, J, m/s
500
What is the unit for work? What is it equivalent to? What does that mean?
Joules (J), J = N*m, it is the amount of energy transferred to an object when a force acts on the object to move it a distance.
500
What are the equations, variables & units to calculate gravitational potential energy & elastic potential energy?
PEg=mgh; PEg is grav potential energy (J), m is mass (kg), g is gravity (m/s2), h is height (m); PEelastic=0.5(k)x^2; PEelastic is elastic potential energy (J), k is spring constant (N/m), x is distance stretched or compressed (m)
500
A) A 64.20 kg man climbs a wall that is 3.650 tall. What is his gravitational potential energy? B) A spring has been stretched 0.255 m and has a spring constant of 685.6 N/m. What is the elastic potential energy?
A) PEg = 2299 J; B) PEelastic = 22.3 J
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