Force
If an object is free-falling, what is the (gravitational) acceleration of the object?
9/8 m/s/s
Anything free falling is falling at the rate of gravity.
Re-arrange the momentum equation to solve for velocity.
An object rolls East for 23 meters, the wind then blows it back 35 meters West. What is the distance the object has traveled?
58 meters
With distance, the direction doesn't matter, so while the object may have a displacement of 12 meters West, distance simply adds up all of the amounts together.
A ball is pushed up a hall 32.5 meters. At the top of the hill, the ball rolls down the hill 41 meters. What is the displacement of the ball?
-8.5 meters
The ball is 8.5 meters behind where it started, thus the negative.
What is the force of a 0.04 kg bullet moving at 430 m/s2?
17.2 N
F = m*a
What is the momentum of a 240 kg tiger that pounces on its prey at 17.2 m/s?
4128 kg m/s
If the speed limit on a highway is 70 miles per hour, is a car that travels 128 miles in 1.75 hours speeding? How far over/under is the car?
Yes, the car is speeding. He is traveling at an average of 73.14 mph, thus he is 3.14 mph over the speed limit.
A dog chases 25 meters after a ball that is thrown. He brings the ball back to the owner and drops it 1 meter in front of the owner. What is this distance the dog traveled?
49 meters.
The dog ran forward 25 meters, and ran back 24 meters, stopping 1 meter from the owner.
A 150 kilogram skydiver jumps out of a plane, what is the weight of the skydiver?
1470 N
Weight (Fg) is mass times gravity. Gravity is 9.8 m/s/s (also known as m/s2).
Mr. Long gets mad when he looks back over the previous scores test. He tosses his 3.4 kg computer at the wall. The momentum of the computer is 24.6 kg m/s. What is the velocity of the computer as flies towards the wall?
7.24 m/s
p = m * v so v = p/m (24.6/3.4)
What is the speed of a runner who runs a 5 kilometers race in 24.62 minutes?
0.203 km/minute (Speed = distance over time)
(This translates to 8.94 miles per hour, or 7 minutes and 55 seconds per mile)
An racecar that has a velocity of 89.5 m/s travels for 10800 s (3 hours). What is the distance that the object travels?
966,600 meters (equivalent to 600 miles)
A 1,500-kg truck has a net force of 4,200 N acting on it. What is the truck’s acceleration?
2.8 m/s/s
F = m * a, so when rearranged
a = F/m
What is the momentum of a 1895 kg car that runs into a deer while traveling at 28 m/s?
p = m*a
53,060 N
A train is traveling at 20.1 m/s as it leaves the city. When it officially gets out the city limits it speeds up to 31.3 m/s. It takes 49 seconds to change speeds, what is the acceleration of the train?
0.229 m/s/s
a = (vf - vi)/t
What is the time it takes for a car that has just started moving at 0.3 m/s at a stop light to obtain a velocity of 26.8 m/s? Assume the car has an acceleration at 4.8 m/s/s.
5.58 seconds
a = (vf-vi)/t therefore t = (vf-vi)/a
(26.8 m/s - 0 m/s) / 4.8 m/s/s
What is the acceleration of a 1.9 kg object with a force of 23.35 N?
12.29 m/s2
F = m * a
so A = F/m
What is the mass of object that has a momentum of 2,550 kg m/s that travels 35 meters in 10 seconds?
728.57 kg
Momentum (p) = m * v
so m = p/v (2550/3.5)
In this problem, we must first get the velocity of the object.
v = displacement/time (35 meters/10 seconds) = 3.5 m/s
An mountain climber climbs 8,848 meters to the top of Mount Everest. He then starts climbing down, and stops almost halfway at 3,985 meters. It takes the climber 27 days to get to the top of the mountain and 12 days to almost halfway down.
What is the speed of the climber? What is the velocity of the climber (in meters/day)?
Speed = Distance/Time (12,833 m/39 days)
Velocity = Displacement/Time (4863 m/39 days)
Speed = 329.05 m/day
Velocity = 124.69 m/day
A man jogs at a velocity of 2.5 m/s west for 1,200 s. He then walks at a velocity of 1.0 m/s east for 500 s and then stops to rest. What is the displacement of the man when he stops to rest?
2500 meters West or -2500 meters
If he jogged for 1200 s at 2.5 m/s West, then he traveled 3000 meters West, he then traveled 500 meters east when he traveled for 500 s at 1.0 m/s. Overall, he finished up 2500 m West of where he started.