Motion in 1D
What is the acceleration of an object that moves at a constant velocity of 20m/s for 5 seconds
No acceleration
Find the components of velocity for an object kicked at 50m/s at an angle 37 degrees above the horizontal
40m/s horizontal velocity
30m/s vertical velocity
How much force is required to keep a 3kg object moving at a constant velocity of 4m/s
NONE (1st Law)
Calculate the acceleration of a 3kg object with a net force of 8N acting on it.
2.66m/s^2
The energy of motion
kinetic energy
Rate of change in velocity
acceleration
The change in momentum
Impulse
F*t
mdeltav
Can an object be moving to the right and accelerating to the left? How?
Yes! The object is slowing down.
In projectile motion, this component of velocity is constant
horizontal
The car
What is the mass of an object that weighs 30N
3kg
37.5 J
The energy that something has by virtue of its position
potential energy
Momentum of a 30kg object moving at 3m/s
90kgm/s
How far does a brick dropped from a bridge fall in 3 seconds?
45m
A 10kg object sits on a ramp angled 37 degrees above the horizontal.
Find the component of gravity that acts down the ramp.
60N
mgsin(theta)
When a car and a truck collide, which one experiences the greater force?
They experience the same magnitude of force
(and impulse)
(and change in momentum)
(the car will have the greater change in velocity though)
12N
90
The slope of a position time graph
velocity
How long will it take to stop a 1000kg truck moving at 3m/s with a force of 300N?
10s
A car accelerates from 20m/s to 30m/s in 5 seconds. Calculate the acceleration and the distance travelled
2m/s^2
125m
A 10kg object sits on a ramp angled 37 degrees above the horizontal.
Find the component of gravity that acts perpendicular to the ramp.
80N
mgcos(theta)
Also the normal force
If the action force is the earth pulling on a person at rest, the reaction force is
the person pulling on the earth.
What is the force required to stop a 2kg sliding initially at 10m/s object over a distance of 50cm?
200N
(you can also use work and energy)
How much power is necessary to do 30J of work in 5 seconds?
6W
Only under the influence of gravity
free fall
How much momentum will a 200g apple have 2 seconds after it falls from a high tree?
4kgm/s
0m/s
Calculate the maximum height and horizontal range for a projectile that is launched at 50m/s at an angle 37 degrees above the horizontal.
Max Height 45m
Horizontal distance: 240m.
How might an object be moving with a constant speed, but also experience a net force.
If the direction the object is moving is changing...(moving in a circle)
A 3kg sign is held in place by a horizontal rope, and another rope that acts at an angle of 37 degrees above the horizontal. What are the tension forces in the ropes?
Horizontal rope 40N.
Prove that the speed of the object at the bottom of a frictionless ramp only depends on the height of the ramp, and not the path of the slide.
mgh = 1/2mv^2
mass cancels out
v at the bottom = sqrt(2gh)
The force that acts from a surface and acts perpendicular to the surface
normal force
A 1000kg truck and a 500kg car collide and stick together. The truck was moving 4m/s north. The car was moving 2m/s south.
What speed will they move after the collision?
2m/s (North)