Question 1
The figure1 below shows a wire wound on a test tube. The windings just touch each other. If the total number of complete loops was found to be 15, and the distance covered by the windings on the test tube is 20cm; find the radius of the wire
Answer
Diameter of wire 20 ⁄ 15 = 1.33
Radius of wire 1.33 รท 2 = 0.67cm
Radius of wire 1.33 รท 2 = 0.67cm
Question 2
A paratrooper flexes his legs when he lands. Explain
Answer
To increase the time take to come to a stop which reduces the rate of change of momentum or reducing the impulsive force producing a small reaction on him by floor
Question 3
A needle may float on clean water but sinks when a detergent is added. Explain
Answer
Clean water has a high surface tension addition of detergent reduces/breaks/lowers the surface tension
Question 4
The mass of a fabric of a large balloon is 100kg. the balloon is filled with 200 m3 of helium and attached to a cable fixed to the ground as shown below
Given that the densities of air and helium are 1.3 kg/m3 and 0.018kg/m3 respectively, determine the tension in the string
Answer
Question 5
Water flows in a pipe of diameter 7cm at a speed of 5m/s. The water then gets to the perforated end which has 20 holes of diameter 0.7cm each.Determine the speed of water jets
Answer
