Physics Final
Please subtract the following and give the answer using significant figures. 0.0572 - 1.0
-0.9 (0.0572 - 1.0 = -0.9428 1.0 ends in the tenths place so -0.9)
What is the x component of a vector that is defined as 1300m at 211o?
-1100 (Ax=Acosθ Ax=1300cos(211)=-1100m)
Subtract the following numbers and give the answer in standard scientific notation (9.2 x 10^-3)-(4.4 x 10^-2)
-3.5 x 10^-2 ((9.2 x 10^-3)-(4.4 x 10^-2) convert both to the larger exponent (0.92 x 10^-2)-(4.4 x 10^-2) subtract -3.5 x 10^-2 Remember Significant Figures)
What is the x component of a vector that is 31 m at 98o?
-4.3 m (31 cos 98 = -4.3 m)
A ball is dropped out of a window and falls for 8.75 s. What is the ball's final velocity?
-85.8 m/s (v0 = 0 m/s a = -9.80 m/s2 t = 8.75 s v = v = v0 + at v = 0 + (-9.80)(8.75) = -85.8 m/s)
A girl walks East at 2.7 m/s. What is the y component of her velocity?
0 m/s (East is 0 degrees Ay = Ainθ Ay = 2.7sin0 = 0 m/s)
A car moves at 18m/s North. What is the x component of the velocity?
0 m/s (North is 90 degrees Ax = Acosθ Ax = 18cos90 = 0 m/s)
What is the acceleration of a projectile in the horizontal or x axis?
0 m/s2 (A projectile does not accelerate in the x or horizontal axis, it only accelerates in the negative y axis.)
Convert the following number from scientific notation to standard notation 7.820 x 10^-4
0.000 782 0 (7.820 x 10-4 move the decimal four times to the left 0.000 782 0 the zero at the end is significant so it must be included)
Convert the following number from scientific notation to standard notation 1.9300 x 10^-3
0.001 930 0 (1.9300 x 10-3 move the decimal 3 times to the left 0.001 930 0 the zeros at the end are significant so they must be included)
Convert 10.4 m to km
0.0104 km (1000 m = 1 km 10.4 m (1 km/1000 m) = 0.0104 km)
A girl is out jogging at 1.75 m/s and accelerates to 3.29 m/s over a displacement of 295 m. What was the girl's acceleration?
0.0132 m/s2 (v = 3.29 m/s v0 = 1.75 m/s a = x = 295 m v2 = v02 + 2ax a = (v2 - v02)/2x a = (3.292 - 1.752)/(2*295) = 0.0132 m/s2)
Add the following and give the answer using significant figures 0.0635 + 0.0502
0.1137 (0.0635 + 0.0502=0.1137 Both numbers have digits in the ten thousandths place so 0.1137)
Convert 125 mL to L
0.125 L (1000 mL=1L 125 mL (1L/1000mL)=0.125 L)
Add the following and give the answer using significant figures 0.1923 + 0.0031
0.1954 (0.1923 + 0.0031=0.1954 both are significant to the ten thousands place so 0.1954)
A tire with an angular velocity of 17 m/s has a centripetal acceleration of 1200 m/s2. What is the radius of the tire?
0.24 m (ac = v2/r r = v2/ac=(17)2/1200 = 0.24 m)
A ball travels around a circular track with a circumference of 0.850m every 2.50s. What is the tangential velocity of the ball?
0.340 m/s (v=x/t v=0.85/2.5=0.340m/s)
A boy skips a rock so that it bounces off the water with a velocity of 3.5m/s at 40.0 degrees. How long will it take to hit the water again?
0.46 s (If a projectile goes up and comes back down to the same height, the y displacement is zero. voy=3.5sin40=2.25 y=vot+1/2at2 0=2.25t+1/2(-9.8)t2 0=2.25-4.9t t=0.46s)
Multiply the following using significant figures. 22.05 x 0.0220
0.485 (22.05 x 0.0220 = 0.4851 0.0220 has three significant digits so 0.485)
A 10.0kg cannon ball is shot with a force of 300.0N by a cannon with a mass of 600.0kg. What is the acceleration of the cannon?
0.500m/s2 (The cannon applies a force of 300.0N on the cannon ball so the cannon ball applies a force of 300.0N on the cannon. F=ma a=F/m=300.0/600.0=0.500m/s2)
Two objects, one with a mass of 50.0kg and the other with a mass of 70.0kg experience a gravitational force of attraction of 3.50x10-7N. How far apart are their centers of mass?
0.817 m (Fg=Gm1m2/r2 r2=Gm1m2/Fg r=√(Gm1m2/Fg) r=√[(6.67x10-11)(50)(70)/3.50x10-7] r=0.817m)
Please subtract the following and give the answer using significant figures. 0.84 - 0.0042
0.84 (0.84 - 0.0042 = 0.8358 0.84 ends in the hundredths place so 0.84)
Convert 1210 Gm to m
1,210,000,000,000 m (1 Gm = 1,000,000,000 m 1210 Gm (1,000,000,000 m/1 Gm) = 1,210,000,000,000 m)
The engine of a riding Lawn mower produces 215N of force. If the lawnmower with a man driving it has a total mass of 189kg, what is the acceleration?
1.14 m/s2 (F=ma a=F/m=215/189=1.14m/s2)
What is the force of gravity between two 40.0kg masses that are separated by 3.00m?
1.19x10^-8N (Fg=Gm1m2/r2 Fg=(6.67x10-11)(40)(40)/(3)2 Fg=1.19x10^-8N)
Multiply the following exponents and give the answer in standard scientific notation. (1.8 x 10^2) x (6.5 x 10^-1)
1.2 x 10^2 ((1.8 x 10^2) x (6.5 x 10^-1) multiply the digits 1.8 x 6.5 = 11.7 Add the exponents 2+(-1)=1 11.7 x 10^1 Check and convert to standard notation if needed 1.2 x 10^2)
Converting the following number from exponential notation to standard scientific notation. 0.123 0 x 10^5
1.230 x 10^4 (Standard scientific notation is one digit and then the decimal place. 0.123 0 x 10^5 So move the decimal one time right. One is subtracted from the exponent. 1.230 x 10^4 The last zero is significant so it must be included in the answer)
A ball is thrown downward with an initial velocity of 12.1 m/s. How long will it take to reach a velocity of -24.5 m/s? (Negative indicates the downward direction)
1.27 s (v0 = -12.1 m/s a = -9.80 m/s2 t = v = -24.5 m/s v = v0 + at t = (v - v0)/a t = (-24.5 - (-12.1))/-9.80 = 1.27 s)
Converting the number 134,000 to Scientific Notation
1.34 x 10^5 (134,000 move the decimal 5 times to the left so exponent becomes +5 Scientific Notation requires 1 digit left of the decimal point 1.34 x 10^5)
A toy car rolls down a slope. If it takes 5.94 s to accelerate from 3.22 m/s to 12.4 m/s, what is the value of the acceleration?
1.55 m/s2 (v0 = 3.22 m/s a = t = 5.94 s v = 12.4 m/s v = v0 + at a = (v-v0)/t a = (12.4 - 3.22)/5.94 = 1.55 m/s2)
How much does the prefix milli multiply the value of a base unit?
1/1,000 (milli is the metric prefix with a value of 1/1,000 or 10-3)
How much does the prefix milli multiply the value of a base unit?
1/1000 (milli is the metric prefix with a value of 1/1,000 or 10^-3)
Multiply the following using significant figures. 200 x 51.30
10,000 (200 x 51.30 = 10,260 200 only has one significant digit so 10,000)
What is the y component of a vector defined as 12.2m at 122o?
10.3 m (Ay=Asinθ Ay= 12.2sin(122) = 10.3m)
A car enters a curve that has a radius of 30.0m. The car has a mass of 1450kg. If the maximum force of friction that can act on the car is 5650N, what is the maximum velocity that the car can travel through the curve?
10.8 m/s (Fc=mv2/r v2=Fcr/m v=√(Fcr/m) v=√[(5650)(30)/1450]=10.8m/s)
What is the tension on a rope causing a 7.50 kg box to accelerate upward at 4.00 m/s2?
104 N (T-W=ma T=ma+W=ma+mg T=(7.5)(4)+(7.5)(9.8)=104N)
Multiply the following using significant figures. 8.26 x 13.0
107 (8.26 x 13.0 = 107.38 both answers have three significant digits so 107)
A man accelerates at 2.52 m/s2 for 3.73s. If his initial velocity was 1.75 m/s, what is his final velocity?
11.1 m/s (v0 = 1.75 m/s a = 2.52 m/s2 t = 3.73 s v = v = v0 + at v = (1.75) + (2.52)(3.73) = 11.1 m/s)
What is the weight of a dog that has a mass of 12.0kg?
118 N (W=mg W=(12)(9.8)=118 N)
Convert 13.7 g to mg
13,700 mg (1000 mg = 1 g 13.7 g (1000 mg/1 g) = 13,700 mg)
Multiply the following using significant figures. 1.2000 x 12000
14000 (1.2000 x 12000 = 14,400 12000 has two significant digits so 14,000)
A man walking at 3.56 m/s accelerates at 2.50 m/s2 for 9.28 s. How far does he get?
141 m (x = v0 = 3.56 m/s t = 9.28 s a = 2.50 m/s2 x = v0t + ½at2 x = (3.56)(9.28) + ½(2.50)(9.28)2 = 141 m)
What is the direction of a the displacement vector for a woman who runs 915 m West and then turns and goes 681 m North.
143o (θ = tan-1(y/x) θ = tan-1(681/-915) = -36.7o if the x component is negative you add 180o -36.7 +180 = 143o)
What must be the mass of a rock if a boy applies a 64N force and causes it to accelerate at 4.51m/s2?
14kg (F=ma m=F/a=64/4.51=14kg)
A little girl sits on a merry-go-round horse. The radius of the horse's path is 10.0m and it is spinning at 3.00m/s. The net centripetal force on the girl is 13.5N. What is the girl's mass?
15.0 kg (Fc=mv2/r m=Fcr/v2 m=(13.5)(10)/(3)2=15.0kg)
A skateboarder starts at 33.7 m/s and comes to a stop in 9.62 s. How far does it get?
162 m (x = v0 = 33.7 m/s v = 0 m/s t = 9.62 s x = ½(v + v0)t x = ½(0 + 33.7)(9.62) = 162 m)
A boy walks north at 11.2 m/s for 14.7s. How far does he get?
165 m, North (v = Δx/Δt Δx = vΔt = (11.2)(14.7) = 165 m)
A man walks 11m West then 12m South. What is the magnitude of his displacement?
16m (West is negative x and South is negative y so these are components of the resultant. R=√[(-11)2+(-12)2]=16m)
A box is at rest on a slope with an angle of 30.0o to the horizontal. If the mass of the box is 20.0kg, what is the Normal force acting on the box? (visual included)
170.N (N-Wperp=0 N=Wperp=mgcosθ N=mgcosθ N=(20)(9.8)cos(30)=170.N)
What net force would be needed to accelerate a 2.95kg bowling ball at 6.25m/s2?
18.4 N (F=ma=(2.95)(6.25)=18.4N)
Divide the following numbers and use significant to determine the answer. 0.0200 ÷ 0.0067110
2.98 (0.0200 ÷ 0.0067110 = 2.98018179 0.0200 has three significant digits so 2.98)
Convert the following number from scientific notation to standard notation 2.0400 x 10^3
2040.0 (2.040 x 103 move the decimal 3 times to the right 2040.0 the zeros at the end are significant so they must be included)
A 50.0kg football player strikes a 75.0kg tackle dummy causing it to accelerate at 3.00 m/s2. What is the force on the football player?
225 N (The football players applies a force on the tackle dummy so the tackle dummy applies the same force on the football player. So calculate the force on the tackle dummy. F=ma=(75.0)(3.00)=225N)
How fast is the rocket going after 45 s? (exponential graph here)
230 m/s (Go straight up on the graph from 45 s to the purple line. Go straight left and the point is between 200 and 300, but closer to 200. The unit is m/s so 230 m/s.)
Please subtract the following and give the answer using significant figures. 300.1 - 56
244 (300.0 - 56 = 244.1 56 ends in the ones place so 244)
Divide the following numbers and use significant to determine the answer. 130.0 ÷ 5.1826
25.08 (130.0 ÷ 5.1826 = 25.0839347 130.0 has four significant digits so 25.08)
A 10.0 kg gun applies a force of 250. N left on a 0.0200 kg bullet. What is the force on the gun?
250.0 N (According to the Third law the forces must be equal in magnitude. So a 250N force on the bullet means a 250 N force on the gun.)
Box A has a mass of 35.0kg and Box B has a mass of 20.0kg. What is the tension on Box A if the acceleration of the system is -2.67m/s2 clockwise? (visual included)
250.N (T-WA=mAa T-mAg=mAa T=mAa+mAg T=(35)(-2.67)+(35)(9.8)=250.N)
If compressing a spring 0.500m causes a force of 1.50N, what is the spring constant of the spring?
3.00 N/m (Fs=kx k=Fs/x=1.5/0.5=3.00N/m)
A girl kicks a soccer ball with a velocity of 13.5 m/s at 35.0o. What is the maximum height reached by the ball?
3.06m (at max height, the final y velocity is 0 voy=13.5sin(35)=7.74 vy2=voy2+2ay y=(vy2-voy2)/2a y=(02-7.742)/2(-9.8)=3.06m)
A discus thrower spins so that his arm makes a radius of 1.5m. If the discus has a centripetal acceleration of 8.0 m/s2, what his speed of the discus as it spins?
3.5 m/s (ac=v2/r v2=acr v=√acr=√(8.0)(1.5)=3.5 m/s)
Divide the following exponents and give the answer in standard scientific notation. (8.8 x 10^-3) ÷ (2.4 x 10^-7)
3.7 x 10^4 ((8.8 x 10^-3) ÷ (2.4 x 10^-7) divide the digits 8.8 ÷ 2.4 = 3.667 Subtract the exponents -3-(-7)=4 3.7 x 10^4 Check and convert to standard notation if needed 3.7 x 10^4)
What is the direction of a vector with an x component of 35 m and a y component of 21 m?
31o (the direction is the angle from the positive x axis. θ=tan-1(y/x) θ=tan-1(21/35)=31o)
A spring with a spring constant of 8.50 N/m is compressed 4.00 m. What is the force that the spring would apply?
34.0 N (Fs=kx Fs=(8.5)(4)=34.0N)
A buffalo roams West for 125 m, then East for 175 m and then West again for 87.2 m. What is the buffalo's displacement.
37 m West (The displacement is the vector sum of the segments East is positive, West negative -125 + 175 + (-87.2) = -37.2 m negative so 37 m West)
A buffalo roams West for 125 m, then East for 175 m and then West again for 87.2 m. What is the buffalo's displacement.
37 m, West (The displacement is the vector sum of the segments East is positive, West negative -125 + 175 + (-87.2) = -37.2 m negative so 37 m West)
What is the centripetal force of a 3.5kg iron ball that spins on a 2.0m long chain at 15m/s?
390 N (Fc=mv2/r Fc=(3.5)(15)2/(2)=390N)
A bird flies East for 1205 m then turns and walks 452 m West. The whole trip takes 185 s. What is the average velocity of the bird?
4.07 m/s East (v = Δx/Δt x is displacement so Δx=1205-452=753m East v=753/185=4.07 m/s East)
A boy on a bicycle rides at 21.1 m/s a distance of 87.9 m. How long does it take?
4.16 s (v = Δx/Δt Δt = Δx/v = 87.9/21.1 = 4.16 s Remember the rule for rounding sig figs when the trailing digit is a 5!)
Converting the number 0.000 458 0 to Scientific Notation
4.580 x 10^-4 (0.000 458 0 move the decimal 4 times to the right so exponent becomes -4 Scientific Notation requires 1 digit left of the decimal point 4.580 x 10^-4 the trailing zero is significant and must be included)
Divide the following exponents and give the answer in standard scientific notation. (4.3 x 10^-5) ÷ (9.4 x 10^3)
4.6 x 10^-9 ((4.3 x 10-5) ÷ (9.4 x 103) divide the digits 4.3 ÷ 9.4 = 0.457 Subtract the exponents -5-(3)=-8 0.457 x 10-8 Check and convert to standard notation if needed 4.6 x 10-9)
What force would be required to pull a 565N woman across the floor if the coefficient of friction between her shoes and the floor was 0.75?
420 N (f=μN N=W=565N f=(0.75)(565)=420N)
Divide the following numbers and use significant to determine the answer. 2300 ÷ 0.0472
49,000 (2300 ÷ 0.0472 = 48,728.8136 2300 has two significant digits so 49,000)
What is the x component of a vector that is 9.5 m at 302o?
5.0 m (9.5 cos 302 = 5.0 m)
Converting the following number from exponential notation to standard scientific notation. 521.3130 x 10^2
5.213130 x 10^4( Standard scientific notation is one digit and then the decimal place. 512.3130 x 10^2 So move the decimal two times left. Two is added to the exponent. 5.123130 x 10^4 The last zero is significant so it must be included in the answer)
Converting the number 5250 to Scientific Notation
5.25 x 10^3 (5250 move the decimal 3 time to the right so exponent becomes +3 Scientific Notation requires 1 digit left of the decimal point and all significant digits must be show (in this case the zero is a place holder and is NOT included) 5.25 x 10^3)
If the force of gravity between two identical masses is 4.00x10-9N and they are 7.00m apart, what is the mass of each object?
54.2 kg (Fg=Gm1m2/r2 Fg=Gm2/r2 m2=Fgr2/G m=√(Fgr2/G) m=√[(4.00x10-9)(7)2/(6.67x10-11)] m=54.2kg)
A Ferris Wheel spins at 13m/s. If it has a radius of 25m, what is the centripetal acceleration of the Ferris Wheel?
6.8 m/s2 (ac=v2/r=(13)2/25=6.8 m/s2)
Subtract the following numbers and give the answer in standard scientific notation (6.9 x 10^7)-(1.2 x 10^6)
6.8 x 10^7 ((6.9 x 10^7)-(1.2 x 10^6) convert both to the larger exponent (6.9 x 10^7)-(0.12 x 10^7) subtract 6.8 x 107 Remember Significant Figures)
Subtract the following numbers and give the answer in standard scientific notation (6.9 x 10^7)-(1.2 x 10^6)
6.8 x 10^7 ((6.9 x 10^7)-(1.2 x 10^6) convert both to the larger exponent (6.9 x 10^7)-(0.12 x 10^7) subtract 6.8 x 10^7 Remember Significant Figures)
A trip is taken that passes through the following points in order Point A 0 m Point B 15.0 m Point C -30.0 m Point D -20.0 m Point E 10.0 m Point F 5.0 m What is the distance from Point A to Point C?
60.0 m (The distance is the sum of the segments lengths. A→B 15-0 = 15 B→C |-30-15| = 45 15+45 = 60.0 m)
A box is at rest on a slope with an angle of 40.0o to the horizontal. If the mass of the box is 10.0kg, what is the parallel component of the weight? (visual included)
63.0 N (Wparallel=mgsinθ Wparallel=(10)(9.8)sin(40)=63.0N)
Using the graph above, what is the mass when the volume is 3 cm3? (linear graph here)
6g (Go straight up from 3 cm3 to the purple line then straight left to find 6. The unit for the y axis is (g), so 6g.)
What would be used as the value for r when solving for the force of gravity if the masses were arranged as above? Each sphere represents a mass, and the values are the radius of the masses and the distance between them.
6m (The distance used in the calculate is from the center of mass to the center of mass. So we must add the radius of each plus the distance separating them. So 4+0+2=6m)
Divide the following numbers and use significant to determine the answer. 253.4 ÷ 35.752
7.088 (253.4 ÷ 35.752 = 7.08771537 253.4 is four significant digits so 7.088)
A projectile is launched horizontally from a cliff that is 10.0 m above the ground with an initial velocity of 5.00 m/s. How far from the base of the cliff does it land?
7.1 m (vx=5.00m/s, voy = 0 y=1/2at2 t2=2y/a=2(-10)/-9.8=2.04 t=1.43 x=vt=(5)(1.4)=7.1m)
Converting the following number from exponential notation to standard scientific notation. 0.007 220 x 10^4
7.220 x 10^1 (Standard scientific notation is one digit and then the decimal place. 0.007 220 x 10^4 So move the decimal three times right. Three is subtracted from the exponent. 7.220 x 10^1 The last zero is significant so it must be included in the answer)
Subtract the following numbers and give the answer in standard scientific notation (7.4 x 10^0)-(9.9 x 10^-2)
7.3 x 10^0 ((7.4 x 10^0)-(9.9 x 10^-2) convert both to the larger exponent (7.4 x 10^0)-(0.099 x 10^0) subtract 7.3 x 10^0 Remember Significant Figures)
Please subtract the following and give the answer using significant figures. 8.070 - 0.72
7.35 (8.070 - 0.72 = 7.350 0.72 ends in the hundredths place so 7.35)
Divide the following exponents and give the answer in standard scientific notation. (8.2 x 10-2) ÷ (1.1x 10-3)
7.5 x 10^1 ((8.2 x 10^-2) ÷ (1.1x 10^-3) divide the digits 8.2 ÷ 1.1 = 7.5 Subtract the exponents -2-(-3)=1 7.5 x 10^1 Check and convert to standard notation if needed 7.5 x 10^1)
A remote controlled plane accelerates to a velocity of 21.0 m/s while covering a distance of 87.4 m in 6.11 s. What was the plane's initial velocity?
7.61 m/s (x = 87.4 m v0 = v = 21.0 m/s t = 6.11 s x = ½(v + v0)t v0 = (2x/t) - v v0 = ((2)(87.4)/6.11) - 21 = 7.61 m/s)
Add the following and give the answer using significant figures 315 + 7200.
7515 (315 + 7200.=7515 the decimal point makes the trailing zeros significant in 7200. So all the digits are significant to the ones place)
What is the net force on a nail if a force of 7.35N is applied West and a force of 3.54N is applied North?
8.16N at 154.3o (magnitude Fx=-7.35 Fy=3.54 F=√(Fx2+Fy2)=√((-7.35)2+(3.54)2)=8.16 direction θ=tan-1(Fy/Fx)=tan-1(3.54/-7.35)=-25.7o x component is negative so add 180 -25.7+180=154.3o 8.16N at 154.3o)
Add the following and give the answer using significant figures 19.7 + 800
800 (19.7 + 800=819.7 800 is only significant to the hundreds place so 800)
Convert 812 Mg to g
812,000,000 g (1,000,000 g = 1 Mg 812 Mg (1,000,000 g/1 Mg) = 812,000,000g)
A girl on a train is running toward the front of a train at 10 m/s. If the train is going 75 m/s on the Southbound tracks, what is the speed of the girl relative to the tracks?
85 m/s South (The girl and the train are both headed in the same direction so relative to the ground we add the two speeds 10+75=85 m/s. The direction would be the direction of the train which is South.)
What is the magnitude of a vector if the x component is 7.5m and the y component is 5.1 m?
9.1 m (R=√[(7.5)2+(5.1)2= 9.1 m)
The prop blades of an airplane have a radius of 5.0 m and with a centripetal acceleration on the farthest edge of 180,000 m/s2. What linear velocity of the point on the blade farthest from the center of rotation?
950 m/s (ac = v2/r v = √(acr) = √((180000)(5.0)) = 950 m/s)
What is the magnitude and direction of the net force on a ball that has a force of 27N South and 18N North applied to it?
9N South (North is positive and South is negative so -27+18=-9N 9N South)
What kind of trend line should be put on this graph? (graph with subtle arch)
A smooth curve (The points form a downward arc so a smooth curve should be used that comes near the points)
Which of the following is correct for velocity?
A vector Depends on Displacement Unit is a meter/second (m/s) (Velocity is a vector and requires both magnitude and direction Velocity is displacement divided by time The correct unit is a meter/second)
An example of a frame of reference would be
All answers are correct (Earth, moving plane, person) (Anything can be used as the frame of reference although some reference frames make describing motion more difficult.)
Which of the following is a field force?
All of these are field forces (electric, magnetic, gravitational) (The field forces are Gravitational, Electric, Magnetic (and Strong and Weak Nuclear). All other forces are contact forces.)
Which equation is valid in the y axis for any projectile?
Any of the four Kinematic Equations (As a projectile has accelerated motion in the y axis any of the four kinematic equations may be applied.)
What is the equation for the x axis of this FBD? (Remember the sign convention discussed in the module)
F-f=ma (Right is positive, left is negative so F-f one is larger than the other so there is an acceleraiton F-f=ma)
The normal would be equal to the weight
If there are no other forces in the y axis and there is no y acceleration then the normal force equals the weight
The Centripetal Force
Is never drawn on a free body diagram. (The centripetal force is Fc=mv2/r The centripetal force is actually the sum of the forces along the centripetal axis. The centripetal force is never drawn on an FBD, the forces that sum to the centripetal force are drawn.)
The SI unit for mass is the
Kilogram (The kilogram is the SI unit for mass. The gram is the base unit of mass, but is not the standard unit. The pound is the English system unit for weight and the Newton is the SI unit for weight.)
Which of the following is NOT a metric base unit
Pound (The pound is an English system unit for weight. An Ampere is the SI unit for current, the Kelvin is the SI unit for temperature, and a Candela is the SI unit for light intensity.)
A man pushes up on a chair to get up. What force is accelerating the man to an upright position.
The chair pushes up the man (The man pushes down on the chair so the chair pushes up on the man.)
Identify what is missing from this graph. (graph with points but no connecting line)
The trend line (All graphs must have a trend line)
What is used to represent an object in an FBD?
a dot (In a free body diagram an object is represented as a dot and the forces as arrows with the direction of the arrow being the direction of the force and the magnitude the relative size of the arrow.)
According to Newton's Third Law of motion, pairs of forces must
act on different objects (Newton's Third Law of Motion states that for every force that acts on an object, there is a reaction force acting on a different object that is equal in magnitude and opposite in direction. These pairs of force must act on different objects.)
What must be done to subtract a vector from another?
add 180o to the angle and then add the vectors (The negative of a vector is one that has the same magnitude but points in the opposite direction. So we add 180 degrees to the angle of the vector and then add.)
Newton's First Law of Motion
all of these answers are correct (is sometimes called the Law of Inertia, applies only if the net force is zero, applies when there is no acceleration) (The first law states that an object at rest remains at rest and an object in motion remains in motion unless acted upon by a net external force. It is often called the law of inertia and only applies to situations with a zero net force and therefore no acceleration.)
Tension
all of these are examples of tension (is any force produced by the pull of a rope, is any force produced by the pull of a wire, is any force produced by the pull of a string) (Ropes, strings, and wires would all be represented by a T for tension. No indication is given as to what is on the other end of the rope, string, or wire)
Mass is a measurement
all of these are true (the resistance to change in motion, how hard it is to change the velocity of an object, of inertia) (Mass is measured in kilograms and is a measurement of the amount of matter an object has. The mass of an object is also the amount of inertia an object has. A greater mass results in a greater inertia.)
The equation v = (x-x0)/(t-t0) is used to calculate the
average velocity (The equation shows change in position over time or displacement over time. That is the average velocity.)
Which of the following is not a requirement of a graph?
connected points (The points on a graph are never connected. A best fit straight line or curve must be used instead)
The area under a velocity vs. time graph is
displacement (The area of a v-t graph is the displacement of the object.)
Multiplying a vector with another vector results in what type of answer?
either a vector or a scalar (Depending on the calculation, a vector multiplied by a vector can yield either a vector or a scalar)
How many significant digits are in the following number? 22000.
five (the decimal point indicates that all the digits are significant)
The normal would NOT be equal to the weight
in all of these cases the normal is NOT equal to the weight (on an elevator accelerating upward, a box accelerating down an incline, on a box dropped off a cliff that hits the ground and bounces upward) (Any additional force in the y axis will cause the normal to be different from the weight)
The force applied to an object can be
in any direction relative to the motion (The net force deals with acceleration, not motion. It can point in any direction and will cause an acceleration in that direction.)
Galileo first developed the concept of
inertia (Galileo is credited with developing the concept of inertia.)
In the equation Δx=x-x0 x0 represents
initial position (the 0, said "naught" indicates the initial value x is the position so this is initial position)
The force of gravity
is between all objects that have mass (The force of gravity is between all objects that have a mass)
The calculated value of static friction
is the maximum value possible (The calculate value of static friction is the maximum that can be present)
The correct unit for force is
kgm/s2 (The derived unit for force is a kgm/s2)
The following equations are for two connected objects in the axis of motion T-f=mAa WB-T=mBa Which of the following equations would be used to determine the acceleration
mBg-f=(mA+mB)a (Add the equations T-f=mAa WB-T=mBa T-f+WB-T=mAa+mBa Simplify mBg-f=(mA+mB)a)
A Field force
occurs when there is no contact between the objects (A field force is one that occurs over a distance without contact. There are very few field forces. All forces are measured in Newton's. While Gravity can only pull, both electric and magnetic fields can push or pull on an object.)
A system consists of multiple objects connected by ropes. How many equations need to be written to solve this problem.
one or two for each object (There must be equations for each object. One or two equations will be generated depending on if there are forces in both axis or just one axis.)
The sides of a right triangle that has any given vector for the hypotenuse are called
resultant (The x and y component are the sides a a right triangle with a vector as the hypotenuse)
How many significant digits are in 122.000
six (122.000 six - the trailing zeros are after a decimal point so they are significant)
Which of the following is the result of centripetal acceleration?
the direction of the velocity constantly changes (Centripetal acceleration causes an object to curve in a circular pathway, so its direction constantly changes.)
The x axis should be labeled with what variable?
the independent variable (the independent variable is always used on the x axis the y axis would be the dependent variable)
If the velocity and acceleration have the same sign then
the object will speed up (The sign of velocity and acceleration indicate the direction of the vector. So if both vectors point in the same direction, the object speeds up.)
What would be the reaction force to a man hitting a punching bag?
the punching bag hitting the man's hand (The pattern is always A applies a force to B and then B applies a force back on A. So if the hand applies a force to the bag, then the bag applies a force to the hand.)
Although we talk about the velocity of an object in Uniform Circular Motion as being constant, we really mean
the speed is constant (The velocity is really the speed in this case, or the magnitude of the velocity vector.)
in the equation Fs=-kx k is
the spring constant measured in N/m (F=-kx the negative sign indicates that the direction is opposite to the displacement x k is the spring constant and measured in N/m x is the amount of expansion or contraction and measured in m)
How many significant digits are in 90600
three (90600 three - the zero that is between 9 and 6 is significant because it is between two significant digits - the trailing zeros are place holders)
Which equation is valid in the x axis for any projectile?
v=x/t (As there is no acceleration in the x axis of a projectiles motion, the only valid equation is v=x/t.)
The equation for Newton's Second Law is written ΣF=ma The symbol sigma (Σ) means
vector sum (ΣF=ma The equation means the vector sum of the forces equals the mass of the object times its acceleration)