Question 1:
You are watching your sister Connie play a tennis match and see the following. Connie runs 10 m straight forward towards the net to return her opponent's shot she covers this distance in 2 seconds. She then runs 6 m straight back in 1.5 seconds in anticipation of the next action. Finally, she runs 5 m in 1 second straight forward for the next shot.
Calculate Connie's velocity for:
- Each of the intervals
- The entire motion
Question 2:
In a busy hospital car park, whilst eagerly searching for a vacant parking space, a driver becomes distracted from driving his sedan car and collides head on with an off duty ambulance.
The sedan car's mass is 1000 kg and just prior to the accident it had a velocity of 10 m/s. The ambulance's mass is 10 000 kg and it had a velocity of 4 m/s.
- What is the final velocity of the vehicles?
- In respect to the two vehicle's position, what is their final direction? Why?
Question 3:
A scientist weights a sample of platinum ore on a scale sitting on his workbench and on a scale inside a water tank. The ore sample's mass as shown on his workbench scale was 92 g, and its apparent mass when submerged in water was 11.5 g. Assume the density of the water to be 1 g/cm3.
- What is the mass of the water that displaced by the ore?
- What is the volume of the object?
- What is the average density of the object?
Question 4:
An object is placed 9.50 cm from a lens with a focal length of 0.11m.
- Calculate the magnification of the object
- Calculate the magnification of the object if its distance is increased by another 10 mm.
Question 5:
Complete the following table:
|
Symbol
|
atomic no.
|
mass no.
|
no. of
protons
|
no. of
neutrons
|
no. of
electrons
|
net charge
|
|
1634Se2-
|
|
|
|
|
|
|
|
|
23
|
51
|
|
|
20
|
|
|
|
|
|
20
|
20
|
|
2+
|
Question 6:
What is the molar volume of a gas at 78 °C and at 1.20 bars?
Question 7:
Ethan your 2½ year old toddler manages to pull a 1.25 kg block in the shape of a car at a constant speed up a frictionless 15° incline. A constant force, F directed up the incline, results from this motion.
- Identify all the forces acting on the toy car and calculate F.
- Find the work done by F in moving the toy car 0.60 m up the incline.
- Find the work done by gravity in moving the toy car over the same distance and path.
Question 8:
You are lying down on your back at the beach, enjoying the tranquil sound of the ebb and flow of the waves, when suddenly a seagull flies towards you at 13.0 m/s emitting a shrill squeal which you hear at 257 Hz.
Assuming the air temperature is 20°C and the speed of sound in the air at this temperature is 343 m/s.
- What frequency did the seagull's shriek emit?
- What frequency will you hear if the seagull emits the same squeal at the same speed while flying away?
Question 9:
Human body cell is mainly composed of water. A cell in the human body typically has a diameter of 10 micrometers at 37°C (which is an acceptable temperature for the body of a healthy person).
What would happen to the cell radius if the person's body temperature decreased to 32°C? Assume the expansion coefficient of water at 20°C is 2.1 ×10-4 °C-1 and that the cells are spherical in shape.
Question 10:
Besides being widely used as a hair dye, hydrogen peroxide H2O2 is the active ingredient (3%) of many solution of antiseptic. H2O2 Readily decomposes into water and oxygen gas when it is applied to wounds. The balanced equation for this chemical reaction is:
2H2O2 (aq)→2H2O(l) + O2 (g)
What approximate quantity of hydrogen peroxide (mass) would be required to produce 1 gram of oxygen gas?
Question 11:
A chemist working for an animal euthanizing centre is experimenting with various types and doses of gas in order to come up with the most suitable lethal dosage. The chemist notices that 2.5 g of chlorine gas takes up a volume of 4.06 liters. Under the same conditions, what volume will 1.35 mol of chlorine take up? Assume the molar mass of chlorine is 35.45 g.