Exercises and problems about forces and their effects on systems: movements and deformations.
Types of forces: at a distance or through contact (4841)
Indicate which of these phenomena are produced by forces at a distance and which are produced by forces through contact:
a) The motion of a train due to magnetic levitation.
b) The deformation of a spring when you attach a weight on it.
c) The skidding of a car on a pool of water.
d) The formation of the aurora borealis.
e) The motion of a cupboard when you push it.
Lengthen of a spring when a force is applied (4843)
A spring has an elastic constant of 120 N/m. Calculate how much it will lengthen by if a force of 35 N is applied.
Classification of bodies: rigid, elastic or plastic (4842)
Classify the following objects into rigid, plastic or elastic bodies:
a) The mechanism of a key of the computer keyboard.
b) Sunglasses.
c) A headband.
d) A steel fork.
e) The bristles of a toothbrush.
f) Bread dough.
Convertion of units: speed of a car (3600)
A car is moving in a straight path at 3 600 meters during 90 seconds. Determine the speed of the car, expressed in km/h.
Acceleration of a car (3583)
A car is increasing its speed from 40 m/s to 70 m/s. What is its acceleration if the time needed was 3 seconds?