Sign. Digits/Conversions
______ significant digits are in 305.200
6
An airplane accelerates down a runway at 3.20 m/s2 for 32.8 s until it finally lifts off the ground. What is the distance traveled before take-off?
1721.34 m
What is the definition of net force?
The combination of all the forces on a single object.
In a rollercoaster, where would the total energy be the greatest?
The energy is equal at all places.
What is the Law of Reflection?
The angle of incidence is equal to the angle of reflection.
θi = θr
_____ significant digits are in 1.7 x 10-3
2
An engineer is designing a runway for an airport. Several planes will use the runway and the engineer must design it so that it is long enough for the largest planes to become airborne before the runway ends. If the largest plane accelerates at 3.30 m/s2 and has a takeoff speed of 88.0 m/s, then what is the minimum allowed length for the runway?
1173.3 m
What are the three laws of motion? (In order)
1) An object in motion will remain in motion or an object at rest will remain at rest without external forces.
2) F = ma
3) If force is applied to something, that something applies the same force back on the object or person but in the opposite direction.
If energy is conserved, then what kind of momentum would it be? Include the formula.
Elastic.
M1V1 + M2V2 = M1V11 + M2V21
What is Snell's Law?
niSinθi = nrSinθr
____ miles are in 6 ft
*Hint there are 5280 ft in a mile
0.00114 miles
For general projectile motion with no air resistance, the horizontal component of a projectile's acceleration is ____.
Always zero
What happens to the velocity of an object if it never experiences an unbalanced force?
The velocity will stay constant if it never experiences an unbalanced force.
If the mass of a car on a hill 50 meters tall is 1375 kg, what is the potential energy?
673750 J
An object of height 10.0 cm is positioned 30.0 cm from a concave mirror with a focal length 8.0 cm. Find the image position.
di = 10.9 cm
_____ years are in 1,000,000 seconds
.32 years
When rolled down a mountainside at 7.0 m/s, the horizontal component of its velocity vector was 1.8 m/s. What was the angle of the mountain surface above the horizontal?
75o
A cheetah can outrun a gazelle in a short straight race, but the gazelle can escape with its life by zigzagging. The cheetah is more massive than the gazelle – explain how this strategy works.
*think of it in terms of inertia
The cheetah must exert a bigger force to change directions than the gazelle because the cheetah has more inertia. This extra force needed for the cheetah to change directions allows the gazelle to get away.
Explain the relationship between potential energy and kinetic energy.
The relationship between the two is that when added, they equal the total energy. This means that if one increases then the other decreases to follow the law of conservation of energy.
The object is positioned 5.3 cm from the mirror with a height of 10.0 cm and a focal point of 8.0 cm. Find the image position and the magnification of the object.
di = 15.7 cm
m = 3.0
*Use significant digits
2026.8
A racquetball thrown from the ground at an angle of 45o and with a speed of 22.5 m/s lands exactly 2.5 s later on the top of a nearby building. Calculate the horizontal distance it traveled and the height of the building.
It traveled 40m and the height of the building is 8.5m.
What is the weight of a 90 kg person on Earth in Newtons? What about the moon?
*Gravity on the moon is 1.6m/s2
On earth: 882 N
On the moon: 144 N
A ball has a speed of 46.95 m/s and a mass of 145.0 grams. What is the kinetic energy of the ball? How would the kinetic energy compare for a ball with half the mass thrown with the same speed?
159.8 J and the kinetic energy would be 1/2 as great.
Light passes from air into a crown glass with an angle of incidence 30◦. What is the angle of refraction?
*A crown glass has an index of refraction of 1.52.
θ2 = 19.2◦