Without calculating the numerical value, simplify:
Simplify:
(34⋅3-2)/3
3(4−2−1)=31 = 3
Which quantity has the same units as velocity?
A. m/s2
B. m/s
C. N/m
D. kg/s
m/s
Where am I from?
Orange County
A vector has: x>0, y<0
Which quadrant does it point toward?
Quadrant IV
A car travels at a constant rate using distance = rate × time. If it travels 150 miles in 3 hours, find its rate.
50 mph
Which is larger?
2+3(4)2+3(4) or (2+3)(4)
(2+3)4=20
2+3(4)2+3(4)=38 (larger)
A length is multiplied by a scale factor of 3.
By what factor does the area change?
9 because 32=9
An object has a horizontal line on a position-vs-time graph.
Is the object moving?
No because a horizontal line has slope zero.
What college am I from?
Seventh!! 7️⃣
An object has an acceleration of 3 m/s² under a net force of 12 N. Find its mass using F = ma.
4 kg
Simplify:
((23)2*2-4)/2-1
23 = 8
Suppose
d=vt
If velocity is measured in m/s and time is measured in seconds, what units must distance have?
m/s * s = m
Two objects have position-time graphs.
Which object is moving faster?
They have the same speed:
4m/s but opposite velocities.
A 20 N vector points 30∘ above the positive x-axis. Which component is larger: Fx or Fy?
Fx=20cos30∘
≈17.3N
Fy=20sin30∘
=10N
A 1,500 g object experiences a net force of 6 N. Find its acceleration in m/s² using F = ma.
1000g=1kg
1500g=1500/1000=1.5kg
F=ma
a=6N/1.5kg
mass = 1.5 kg, so a = 4 m/s²
What kind of dog do I have?
golden retriever
A cube has side length 3 cm. Every side is doubled.
A student says:
"The volume doubles because the side length doubled."
Is the student correct?
No since volume scales cubically.
Vnew = 23Vold
8
During which segment is the object moving fastest? What is its velocity during that segment?
For Segment A:
v=8−0/2−0
=4 m/s
For Segment B:
v=0
For Segment C:
v=2−8/7−5
=−3 m/s
Compare the magnitudes:
∣4∣>∣−3∣>0|4|>|-3|>0
Therefore:
Segment A, with a velocity of +4 m/s
A vector points directly upward.
What are its x- and y-components?
x = 0, y > 0
An object in equilibrium experiences four forces along the same line: 30 N to the right, 12 N to the left, 8 N to the left, and an unknown force. Find the magnitude and direction of the unknown force.
10 N to the left (-10N), since 30 − 12 − 8 + x = 0
Solve for x:
(3x+6)/4 - (x-2)/3 =2x - 5
x = 86/19
A runner travels 100 m in 12.5 seconds.
Another runner travels 0.12 km in 14 seconds.
Who has the greater average speed?
Runner 1:
v1=100/12.5
= 8m/s
Runner 2:
0.12km=120m
v2=120/14
≈8.57m/s
Therefore:
Runner 2
A position-time graph is a straight line passing through (2,8) and (6,20). Assume the time is given in seconds and position is given in meters.
Velocity:
v=20−8/6−2
=3m/s
Equation:
x(t)=3t+b
Using (2,8):
8=2(3)+b
b=2
Therefore:
x=3t+2
At t=10
x=32m
x(10)=32m
Two forces act on an object:
A=40N at 60∘ B=25N at 150∘
Find the x-component of the resultant.
Ax=40cos60∘=20
Bx=25cos150∘≈−21.7
Therefore:
Rx=20−21.7
Rx=−1.7N
Two cars start from rest.
After the same amount of time, how do their velocities compare?
v=at
vB=2vA
So Car B has twice the velocity of Car A.