Linear motion
Which physical quantity must be described using both magnitude and direction?
vector quantity
What is Newton's First Law
An object at rest remains at rest and an object in motion remains in motion unless acted on by an external force
What is the formula of momentum
mass x velocity
What is the period?
the time for one complete revolution.
At what angle between the applied force and the lever arm is the torque maximum?
90o
A runner is running around a rectangle track with length = 50 meters and width = 20 meters. He travels around the rectangle track twice, finally running back to the starting point. If the total time he takes to run around the track is 100 seconds, determine average speed and average velocity.
Average speed=2.8 m s-1
Average velocity=0 m s-1
Three forces act on a block which is sliding down a slope at constant speed. W is the weight, R is the reaction force at the surface of the block and F is the friction force acting on the block. In this situation:
A. there must be an unbalanced force down the plane.
B. W = R
C. F = W
D. the resultant force on the block is zero
D
A stopper of mass 8 g leaves the opening of a container that contains pressurized gas.The stopper accelerates from rest for a time of 16 ms and leaves the container at a speed of 20 m s–1. What is the order of magnitude of the force acting on the stopper?
101 N
A constant torque acts on a bicycle wheel. The wheel accelerates from rest to a final angular velocity of 16 rad s−1 in a time of 4.0 s. What is the angular displacement of the wheel during the acceleration?
32 Rad
A solid cube of side length L and weight W is initially supported by a frictionless horizontal spindle that passes through the centres of two opposite vertical faces of the cube.
The spindle is then removed and repositioned so that it passes through the cube at a point located a distance L/4 to the right of its original position, measured horizontally from the centre of the cube.
When viewing one of the vertical faces of the cube, determine the magnitude of the torque of the couple that must be applied to prevent the cube from toppling under its own weight.
WL/4
An astronaut on the Moon, where there is no air resistance, throws a ball in projectile motion. The ball’s initial velocity has a vertical component of 8.00 m s–1 and a horizontal component of 4.00 m s–1. The acceleration of free fall on the Moon is 1.62 m s–2. What is the speed of the ball 9.00 s after being thrown?
7.70 m s-1
A uniform pipe of length 0.40 m and constant cross-sectional area 0.012 m² is open at one end and floats vertically in a liquid.
When the pipe is floating, one-quarter of its length is above the surface of the liquid.
The weight of the pipe is 32 N.
Assuming the pipe is in equilibrium and neglecting the weight of any liquid inside the pipe, determine the density of the liquid.
910 kgm–3
A ball of mass 0.20kg, travelling in the x-direction at a speed of 0.50 ms–1, collides with a ball of mass 0.30 kg travelling in the y-direction at a speed of 0.40 ms–1. The two balls stick together after the collision, travelling at an angle θ to the x-direction.
50o
A mass at the end of a string is moving in a horizontal circle at constant speed. The string makes an angle θ to the vertical. What is the magnitude of the acceleration of the mass?
a = g tan θ
The moment of inertia of a uniform circular disc of radius 'R' and mass 'M' about an axis touching the disc at its diameter and normal to the disc will be
3/2 MR2