EMILLECT 2024/2025 ACADEMIC YEAR ©2024 EMILLECT. ALL RIGHTS RESERVED FIRST PUBLISH OCTOBER, 2024
CHST Study Guide with Complete Solutions
If angle A is 63.4 deg, What is the length of side C? Tangent side of angle A is 5, and adjacent
side is 10. - Answer✔✔-Sin A = a/c, Sin 63.4=10/c, c=10/sin 63.4=11.2
What is the angle of the ramp that rises 4 feet in a 10 feet run? - Answer✔✔-Tan A = a/b, Tan A
= 4/10, A = Arc Tan [4/10], A = 21.801
Based on the allowable limits in the table below if the noise in a work area was 95 dBA for 3
hours, 90 dBA for 5 hours and 85 dBA for 2 hours, is the allowable limited exceeded? -
Answer✔✔-C = Time exposed and T = Allowable time exposed
C1/T1 + C2/T2 + C3/T3 + Cn/Tn
Anything > 1 is exposure not allowed
3/4+5/8+2/no limit = 1.375 > 1
If a vessel contains 70% air and 30% hydrocarbons what is the oxygen content of the vessel? -
Answer✔✔-Normal air contains 21% oxygen by volume. The vessel only contains 70% normal
air. Therefore 0.7x.21 = 0.147 or 14.7%
Compute the TWA concentration from the following measurement data: 0700-1000 hrs. @ 100
ppm; 1000-1200 hrs. @ 200 ppm; 1300-1400 hrs hrs. @ 0 ppm; and 1400-1600 hrs. @ 100 ppm.
- Answer✔✔-C = PPM exposed to and T = Time exposed to
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Sum of (C1xT1) + (C2xT2) + (C3xT3) + (C4xT4) divided by the Sum of T1 + T2 + T3 + T4
300+400+0+200=+2+1+2=8 = 112.5
If a job site operation results in a $45,000 loss every 3 years, what is the expected loss over a
period of years? - Answer✔✔-Solve for yearly loss, 45,000/3 = 15,000
Multiply by 12, 15,000x3 = 180,000
A radioisotope has a half-life of 1 year. How many years will it take to reduce the initial activity
to less than 10%. - Answer✔✔-4 years
100% 1 year = 50%, 2 Years = 25%, 3 years = 12.5, 4 years = 6.25%
How much does a 55 gallon drum of acid weigh, if the specific gravity of the acid is 2.1. Note
water weighs 8.34 lbs per gallon? - Answer✔✔-Specific gravity (SG) is the ratio of a substance
compared to an equal volume of water. In this case one gallonof acid weighs 2.1 time the weight
of water. The Formula then becomes # of gallons x 8.34 x SG.
55X8.34x2.1 = 963.3 lbs
A 1200 lbs load is lifted with a 2 leg sling whose legs are at 30 Deg angel with the load. The
stress on each leg is? - Answer✔✔-Sin A = a/c, c=a/sin A, c=600/sin 30, c=1200 lbs
A 20,000 lbs load is lifted with a 2 leg sling whose legs are at 60 Deg angel with the load. The
stress on each leg is? - Answer✔✔-Sin A = a/c, c=a/sin A, c=10000/sin 60, c=11547 lbs
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A 25,000 lbs weight is suspended by two equal length cables as a bar with two hoist lines
forming a triangle a 100 Deg angle. What the stress on each line? - Answer✔✔-Separate into a
single right triangle carrying half of the load. Reorient and label (the 40 Deg is complimentary)
Sin A = a/c, c=a/sin A, c=12500/sin 40, c=19450 lbs
Calculate the WBGT index from the following information. Outdoor temperature of 98 Deg, wet-
bulb temperature of 90 Deg, and dry-bulb of 94 Deg. - Answer✔✔-Outdoor Formula:
0.7WB+0.2GT+0.1DB
0.7x98+0.2x90+0.1x94 = 92
Calculate the WBGT index from the following information. Indoor temperature of 91 Deg, wet-
bulb temperature of 97 Deg. - Answer✔✔-Indoor Formula: 0.7WB+0.3GT
0.7x87+0.3*91 = 112.1
How much force does it take to push a handcart that weighs 90 lbs and is carrying a 150 lbs
load? the cart wheels have a coefficient of friction of .09. - Answer✔✔-F=(Micro)N
F=0.09x(90+150)
F+21.6lbs
Your plant manufactures electronics parts. These parts are moved throughout the plant using
four wheel handcarts, which weigh 65 lbs. the coefficient of friction for the cart is 0.12. What
weight can be carried by the cart with 22 lbs pushing force? - Answer✔✔-F=(Micro)N
22=0.12xN
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22/0.12=N
N=183
N=183-65(cart)=118 lbs
What is the Log of Work-Related Injuries and Illnesses? - Answer✔✔-OSHA Form 300
What is the Summary of Work-Related Injuries and Illnesses? - Answer✔✔-OSHA Form 300A
What regulation states that employees have the right to review your injury and illness records? -
Answer✔✔-29 CFR 1904.35
What is considered a work-related injury or illness? - Answer✔✔-If an event or exposure in the
work environment caused or contributed to the condition or significantly aggravated a
preexisting condition.
Which work-related injuries and illnesses should you record? - Answer✔✔-Death, loss of
consciousness, days away from work, restricted work activity or job transfer, or medical
treatment beyond first aid.
When do you need to determine whether a workplace injury or illness is recordable? -
Answer✔✔-Within 7 days
Under what circumstances should you NOT enter the employee's name on the OSHA Form 300?
- Answer✔✔-Injury or illness to intimate body part or reproductive system, injury or illness from
a sexual assault, Mental Illness, HIV infection, hepatitis, or tuberculosis, needle stick injury or
cut from sharp object contaminated with blood
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