Motion & Graphs
On a position vs time graph what does the slope represent?
Velocity because V = change of x / change in time
A car travels at a constant 7m/s for 4s. How far does it travel?
28m
State Newton’s Second Law.
F=ma
Net force causes acceleration.
Which are vectors: distance, velocity, speed, forces?
Velocity and Force
(They must have magnitude and direction)
A 15 kg object rests on a horizontal surface. Find its weight and normal force.
147N
An object's position stays at 7m from t = 2s to t = 6s. What is the velocity during that interval?
V = 0m/s, object at rest
A car starts from rest and accelerates at 3 m/s^2 for 5 s. Find its final velocity
15m/s
A 25 kg box experiences a net force of 75 N. Find its acceleration.
3m/s^2
A vector has components 6 and 8. Find its magnitude.
10
A 20 kg box slides across a horizontal floor with uk=0.25. Find the kinetic friction force.
49.1N
An object moves from x = 3m to x = 12m, then back to x = 5m. Find total distance and displacement
Distance = 16m
Displacement = +2m
A cart starts at 4m/s, accelerates at 2m/s^2, and moves for 6s. Find its displacement.
60m
A 90 kg couch is pushed right with 70 N while another force pushes left with 25 N. Ignore friction. Find the net force and acceleration.
0.50m/s^2 right
A force of 50 N acts at 30 degree above horizontal. Find its x- and y-components.
Fx= 43.3N
Fy=25n
A box has a maximum static friction of 35 N. You push it with 20 N and it does not move. What is the actual static friction force?
20N fs does not automatically equal maximum static friction
A velocity-time graph shows +4m/s for 5s, followed by -2m/s for 3s. Find the net displacement.
14m
A block travels 2.8m up a ramp before momentarily stopping. Its acceleration is -1.4m/s^2. Find its initial velocity.
2.8m/s
A 40 kg hanging object is motionless. Find the tension in the rope.
392.4N
A projectile is launched at 20m/s at 60 degrees. Find vix and viy
Vix = 10m/s
Viy = 17.3m/s
A cart moves at constant speed 0.50m/s. Another cart starts from rest at the same position. They must meet 3.0 m away. Find how long the constant-speed cart takes and the acceleration the second cart needs.
0.167m/s^2
Velocity increases linearly from 2m/s to 8m/s over 3s. Find the acceleration and displacement during the interval.
A = 2m/s^2
Displacement = 15m
A runner starts from rest and accelerates at 3.5m/s^2 for 3s. She then continues at constant speed. If the race is 100 m, find the total race time.
11.02
A 1500 kg crate is lifted by two upward tension forces of 10,000 N each. Find the crate’s acceleration and direction.
3.52m/s^2 upward
A projectile is launched at 25m/s at 40 degree. Find its horizontal and vertical velocity components after 1.5 s.
Vx=19.2m/s
Vy=+1.36m/s
A projectile is launched at 30m/s at 35 degree Find its horizontal component, vertical component, time to highest point, and state the vertical velocity and acceleration at the top.
Horizontal = 24.6m/s
Vertical = 17.2m/s
Highest Point = 0m/s
Projectile's Horizontal = 24.6m/s