Answer:
below
Explanation:
Ice melts, meaning it has a watery layer upon its surface. This allows things to be moving like they are on a liquid but it has the solidity of a solid. The thin metal of the ice skates also decrease the surface area meaning it exerts more force but in turn, it allows you to move faster and further reduces friction.
Langerhans cells exist on the surface of the skin. They help to protect you by keeping dangerous microbes from entering your body. Langerhans cells do this in two very different ways: by protecting your skin from infection and also by stimulating allergic reactions.
Answer:
a. negative
b. zero
Explanation:
work is the change in the energy of a system due to external forces
work is done when a force moves a load through a distance in the direction of the force
The work done by a force on a system is positive when the force and the force displacement point in the same direction and negative when they point in opposite directions
in the scenario we are considering in the question, the force (the hand) moves the block vertically upwards but the displacement of the block reduces (in the opposite direction) since it decelerates. as such the work done by gravity on the block is negative.
the work done on the block is zero if the system consists of the block and the earth because there is no gravitational force exerted on the system
Average speed = (distance covered) / (time to cover the distance)
Average speed = (4 meters) / (5 seconds)
Average speed = (4/5) (meters/seconds)
Average speed = 0.8 m/s
Answer:
Explanation:Let me tell you the logic you need for this: If the boy hears an echo, this means ... 100 m from a tall building claps his hands and hears an echo 0.6 seconds later. ... you can find the rate of travel (meters travelled per second) dividing the total ... the speed of sound in a hypothetical silent craft
