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100
You are walking at a constant velocity of 5 m/s. What is your displacement after 6 seconds.
v= 5 m/s d=vt t= 6 s d= ? d=(5m/s)(6s) d= 30 m
100
Using dimensional analysis, show how many seconds are in a week.
1 week x (7 days / 1 week) x (24 hours / 1 day) x (60 minutes / 1 hour) x (60 seconds / 1 minute)= 604,800 seconds in one week
100
Is velocity a vector or scalar quantity?
Velocity is a vector quantity because it has both magnitude and direction. (ie. 6 m/s east)
100
Using dimensional analysis, show how many seconds are in a day.
1 year x (365.24 days/1year) x (24 hours/1 day) x (60 minutes/1 hour) x (60 seconds/1 minute)= 31,570,560 seconds in a year
100
What is the fundamental unit for length?
The fundamental unit for length is meters.
200
What would be the final velocity of a car the has an initial velocity of 8 m/s traveling at an acceleration on 4 m/s^2 for 9 seconds?
vf=? vf=vi+at vi=8 m/s a= 4 m/s^2 vf=8m/s+(4m/s^2)(9s) t= 9 s vf=8m/s+36 vf=44 m/s
200
What is the fundamental unit for mass?
The Fundamental Unit for mass is kilograms.
200
You, with a mass of 45 kg, are in an elevator. From rest, it begins to accelerate at 3 m/s^2. What is the net force applied?
F(net)=? F(net)=ma m=45 kg a=3 m/s^2 F(net)=(45kg)(3m/s^2) F(net)=135N
200
An applied force of 200 N pushes a box to a displacement of 65 meters. How much work is exerted on the box?
W=? W=Fd d=65 m F=200 N W=(200N)(65m) W= 13000 J
200
A car, with a mass of 2000 kg, travels at 20 m/s. What is the momentum of the car?
p=? p=mv m=2000 kg v=20 m/s p=(2000kg)(20m/s) p= 40,000 Nxs
300
Is time a vector or scalar quantity?
Time is a scalar quantity because it has magnitude, but no dierction.
300
What is the centripetal acceleration of a swing when the velocity is 2 m/s and the radius is 4 meters?
a(c)=? a(c)=v^2/r v=2 m/s r=4 m a(c)=2m/s^2/4m a(c)=4/4 a(c)=1m/s^2
300
A train moves with a speed of 1.4 m/sec. The mass of a train is 40,000 kg. What is the momentum of the train?
p=? p=mv m=40,000 kg v=1.4m/s p=(40,000 kg)(1.4 m/s) p=56,000 Nxs
300
You are walking at a constant velocity of 15 m/s. How long does it take for you to have a displacement of 60 meters if you walk away from your starting point?
d= 60 m d=vt v= 15m/s t= ? 60m=(15m/s)(t) t=4s
300
What would be the final velocity of a car with a initial velocity of 7 m/s, traveling at an acceleration on 9.81 m/s^2(nothing to do with gravity) after traveling 50 meters?
a=9.81 m/s^2 vf^2=vi^2+2ad vi= 7 m/s d =50 m vf^2=7m/s^2+2(9.81m/s^2)(50m) vf= ? vf^2= 49+981 vf^2= 1030 vf=32.09
400
A 2000 kg car has a velocity of 30 m/s. What is its momentum?
m=2000 kg p=mv v=30 m/s p=? p=(2000kg)(30m/s) p=60,000 Ns
400
An applied force of 40 N pushes a box to a displacement of 50 meters. How much work is required for this to occur?
W=? W=Fd d=50 m F= 40 N W=(40N)(50m) W=2000 J
400
What is the centripetal acceleration of a swing when the velocity is 5 m/s and the radius is two meters?
a(c)=? a(c)=v^2/r v=5 m/s r=2 m a(c)=5m/s^2/2m a(c)=25/2 a(c)=12.5m/s^2
400
A 1250 kg car has a velocity of 65 m/s. What is its momentum?
m=1250 kg p=mv v=65 m/s p=? p=(1250 kg)(65m/s) p=81250Ns
400
You, with a mass of 50 kg, are in an elevator. From rest, it begins to accelerate at 2 m/s^2. What is the net force applied?
F(net)=? F(net)=ma m=50 kg a=2 m/s^2 F(net)=(50kg)(2m/s^2) F(net)=100N
500
Answer Both Questions 1) Two forces, both measuring 6N, push a block at a 0 degree angle. What is the net force being pushed on the block? 2) Two forces, both measuring 6N, push a block at opposite angles. What is the net force being pushed on the block?
1) F=6N Because both forces are pushing the block at the same angle, you must add the vectors together. F(net)=F(1)+F(2) F(net)=6N+6N F(net)=12N 2) F=6N Because both forces are pushing the block at opposite angles, you must subtract the vectors. F(net)=F(1)-F(2) F(net)=6N-6N F(net)=0N
500
Answer both questions 1)A 1500 kg car traveling at a wall going 5 m/s^2 hits a wall? What is the force of the car? 2)A 1500 kg car traveling at a wall going 10 m/s^2 hits a wall? What is the force of the car?
1) F=? F=ma m=1500kg a=5.0m/s^2 F=(1500kg)(5.0 m/s^2) F= 7500 N 2) F=? F=ma m=1500 kg a=10.0 m/s^2 F=(1500 kg)(10.0 m/s^2) F=15000 N
500
Answer both questions 1) A ball is dropped straight down from rest. What is the velocity of the ball after 3 seconds, assuming no air resistance? 2) A ball is dropped straight down from rest. What is the velocity of the ball after 4.5 seconds, assuming no air resistance?
1) a=-9.81 m/s^2 v(f)=v(i)+at t=3 s v(f)=? v(f)=0m/s+(-9.81 m/s^2)(3 s) v(i)=0 v= -29.43 m/s 2)a=-9.81 m/s^2 v(f)=v(i)+at t=4.5 s v(f)=? v=0m/s+(-9.81 m/s^2)(4.5 s) v(i)=0m/s v= -44.15 m/s
500
Answer both questios 1)A ball is thrown off a cliff. Its takes 3.5 seconds to hit the ground. How high is the cliff? 2)A force of 20 N is applied to box. The force brings the box to a displacement of 25 meters. How much work was exerted on the box?
1)d=? d=(vi)(t)+(1/2)(a)(t)^2 a=-9.81m/s^2 t=3.5s d=(0m/s)(3.5s)+(1/2)(-9.81m/s)^2(3.5)^2 vi=0m/s d=(-4.905m/s^2)(12.25s) d=60.09 m 2) W=? W=Fd F=20 N d=25m W=(20N)(25m) W=500J
500
Answer both questions 1)A 1.5 kg ball moving at 8.0 m/s south, strikes a 2.0 kg ball moving at 3.0 m/s south. If the velocity of the 2.0 kg ball after the collision is 4.5 m/s south, what is the velocity of the 1.5 kg ball? 2) A ball is thrown off cliff at a velocity of 15 m/s. It land 30 meters from the ground. How long does it it take the ball to fall to the ground
1)m(1)=1.5kg p (before) = p (after) m(2)=2.0kg mv+ mv = mv + mv v(1)=3.0m/s (1.5)(8) + (2)(3)=(1.5)(v) +(2)(4.5) v(2)=? 12+6 =1.5 v+9 9= 1.5 v v= 6.0 m/s south 2)vi=15m/s d=(vi)(t)+(1/2)(a)(t)^2 d=30m a=0m/s^2 30m=(15m/s)t+ (1/2)(0m/s^2)(t)^2 t=? 30m=(15m/s)t 2s=t