Reference no: EM132728308

PHYS211 Physics For Science & Engineering - Taylors University

Question 1

An object has been projected from the edge of a cliff 208 m above ground level with an initial speed of 70 m/s at an angle of 30.0º with the horizontal, as shown in Figure Q1. Determine:
a) the time taken by the projectile to hit point P at ground level,
b) the range X of the projectile as measured from the base of the cliff.

At the instant just before the projectile hits point P, find
c) the horizontal and the vertical components of its velocity, Vfx and Vfy (as labelled in figure),
d) the magnitude of the velocity, V,
e) the angle made by the velocity vector with the horizontal.
f) the maximum height above the base reached by the projectile.

Question 2
Two boxes have been connected through a pulley as shown in Figure Q2. The two boxes are each initially 7.50 m above the ground, and the massless frictionless pulley is 20 m above the ground. Determine:
(a) the acceleration of the whole system when it is released,
(b) the final velocity of the 8 kg box,
(c) the maximum height the 5 kg box can reach after the system is released. (HINT: Once the heavier box hits the ground, the tension force disappears, and the lighter box is in free fall)

Question 3
In a car accident, a vehicle hits a huge concrete obstacle at 200 miles per hour. The car weigh 1.35 tonnes and takes 4500 ms from the time of impact until it is brought to rest. Determine:
(a) the average force exerted on the car by the obstacle,
(b) the average deceleration of the car. Given that 1 mile per hour (mph) = 0.44704 m/s.

Question 4
As shown in Figure Q4, a disk is rotating at 15800 rpm is brought to rest by a frictional torque of 180 Nm. If the mass of the disk is 3 kg and its diameter is 0.13 m, determine:
a) the number of revolutions will the disk turn before coming to rest,
b) the time it takes to complete the rotation.

Question 5
Assume a spaceship with diameter of 50 m, calculate:
a) the velocity that a cylindrical spaceship must rotate if astronauts are to experience simulated gravity of 1.20 g,
b) the time needed for one revolution.

Question 6

Consider a ladder with a painter climbing up it, as shown in Figure Q6. If the mass of the ladder is 20 kg, the mass of the painter is 60 kg, and the ladder begins to slip at its base when her feet are 80% of the way up the length of the ladder, determine:
i) the force Fw,
ii) the force Fc.

Question 7

Equipment:
Mass carriers (2 small, 1 large) with slotted mass, one 0.5 kg mass, one spirit level, one protractor, one ruler, two retort stands, sewing thread, pencil, eraser.

Procedures:
Part 1:
a) Set up the apparatus as shown in Fig. A.
b) Hang a mass of 0.5 kg and a mass carrier with a string of 15 cm long.
c) Carefully add mass 0.05 kg at a time until the string breaks.
d) Record the total mass as M1.
e) Repeat procedure (a) to (d) for three times.

Part 2:
f) Repeat procedures (a) to (c) with a string of 26 cm long.
g) Record the total mass as M2.
h) Repeat procedure (f) to (g) for three times.

Part 3:
i) Set up the apparatus as shown in Fig. B.
j) Mark the location of the retort stands with pencil.
k) Place a ruler on top of the two small mass carriers.
l) Using the spirit level, make sure that the ruler is placed horizontally.
m) Hang a mass of 0.5 kg and a mass carrier with two strings as shown.
n) Using a protractor, measure and record the angles α and β.
o) Carefully add mass 0.05 kg at a time until the string AB breaks.
p) Record the total mass as M3.
q) Repeat procedure (m) to (p) for three times.

Discussion: (Please answer the following questions. No need copy questions)
7.1 The objectives of the lab report are missing. Please write THREE objectives for this lab.

7.2 Comparing Tmax,15 and Tmax,26 , does the length of the string affect the maximum tension (or the maximum load) of the string system? Explain.

7.3 What is the maximum allowable tension in the string for experiment Part 1, Part 2 and Part 3?

7.4 Explain which set up (one-string or two-strings system) can withstand more loads.

7.5 In the two-strings system, string AB always breaks before string BC as they are identical from material, diameter and should have the same maximum allowable tension? Explain.

7.6 For the two-strings system, what is the sum of the tensions in y-direction? Is its magnitude same with the magnitude of the weight, W3? Explain.
Conclusion:

7.7 Comment on the relationship between the maximum load and the sum of tensions in

y-direction for the 2 strings system.

7.8 Comment on the validity of resolving the tensions to their x and y components.

7.9 Comment on possible experimental error(s).

Attachment:- Physics For Science.rar