Force and pressure
formula to calculate force
F = mg
What is energy?
It is the ability to do work.
Upon heating, which of the following expands the slowest?
A. carbon dioxide
B. water
C. plastic bag
C
The SI unit of current
Ampere
formula to calculate pressure and its unit
P = F/ A, unit of pressure is Pa
Calculate work done if a man use 1000N of force to push a wall.
0 J.
Which of the following medium prevent conduction and convection?
A. air
B. rubber
C. vacuum
C
In a series circuit, the batteries provide 6V of voltage and the resistance of two light bulbs is 3 ohm each. Calculate total amount of current flow through the circuit.
2A
list two non-contact force and one contact force
gravitational force, magnetic force and friction
Why a man does no work as he pushes against a wall?
Although the man applied force to push the wall, but it never move.
Grass --> grasshopper --> fox --> tiger
Which organism is in the third trophic level?
fox
In a parallel circuit, the batteries provide 6V of voltage and the resistance of two light bulbs is 3 ohm each. Calculate total amount of current flow through the circuit.
4A
7.6 N
State energy conversion when a house use solar energy to charge a powerbank.
Light energy --> electrical energy --> chemical potential energy
What is the relationship between a sea anemone and a clown fish?
mutualism
How to place ammeter and voltmeter in a circuit? Explain.
Ammeter in series while voltmeter in parallel. Ammeter has very low resistance while voltmeter has high resistance
A nail. As the nail has smaller contact area with the surface of a table, thus the pressure exerted will be greater.
Calculate work done by a man as he walk up the stairs from level one to level two. The distance between each level is 4m and his body mass is 70kg.
2800J
Polar bear has white fur. Explain how its fur reduce heat loss.
White is poor radiator of heat. Less heat is radiated from polar bear's body so as to keep it warm.
The power rating of a table lamp is 30W. If Ben uses his table lamp everyday for 8 hours and the cost for electricity is 28 cents per unit. Calculate the amount he has to pay for using the lamp in September.
201.6 cents / $2.02