- #1
Underdog_85
- 10
- 0
Q1: Assuming friction force to be negligibly small, what will be the acceleration in m/s^2 of a 45kg skater when propelled by a force of 250N?
My attempt
Data:
F-250N
m-45kg
a-m/s^2
Formula:
F=ma
a=F/m
a=250N/45kg
a=5.555
a=5.6m/s^2
Q2: a 0.5kg mass on a horizontal frictional free table is accelerated by a force from a string passing over a pulley and attached to a mass of 1.5kg hanging vertically.
My attempt
Data:
m-0.5kg
hanging m-1.5kg
formula:
F=F1+F2
F=0.5kg+1.5kg=2.0kg
F=ma
F=2.0kg(9.80m/s^2)
F=19.6 rounded to 20N
My attempt at B)
Data:
F=19.6N
m=2kg
a=?m/s^2?
Formula:
F=ma
a=F/m
a=19.6N/2kg
a=9.8 rounded to 10m/s^2
Q3: A 1200kg truck is moving at 108km/h and stops within a distance of 91m
a)What is the acceleration?
My attempt
Data:
m-1200kg
Vi-108km/h--->converted to 30m/s
Vf-0
s-91m
Formula:
2as=Vf^2+Vi^2
a=Vi^2/2s
a=(30m/s)^2/2(91m)
a=900m^2/s^2/182m
a=-4.9m/s^2(negative because it decelerated)
My attempt at part B)What is the coefficient of friction?
Formula:
Ff=uFn
u=Ff/Fn
u=4.9m/s^2/1200kg
u=0.00408
Q4: you are pulling a 3.0slug crate and a sliding friction is known to be 55lb. what is the acceleration o the crate when the pulling force is?
a)55lb, b)75lb and c)105lb
My attempt at a)
Date:
m: 3.0Slug
F:55lb
a:?m/s^2?
Formula:
F=ma
a=F/m
a=55lb/3.0slug
a=18ft/s^2
My attempt at part b)
Data:
m: 3.0slug
F: 75lb
a: ??
formula:
F=ma
a=F/m
a=75lb/3.0slug
a=25ft/s^2
My attempt at part c)
Data:
m: 3.0slug
F:105lb
a-??
Formula:
F=ma
a=F/m
a=105lb/3.0slug
a=35ft/s^2
Q5: During a training exercise, Brian who weighs 75kg skydives and parachutes from a stationary helicopter. What is the acceleration when the air drag is a)500N, b)1500N, and c)Equal to his weight
My attempt at a)
Data:
Fw:75kg
g:-9.80m/s^2
m: 500N
a=?
Formula:
F=ma
a=F/m
a=500N/75kg
a=6.66m/s^2
My attempt at b)
Formula:
a=F/m
a=1500N/75kg
a=20m/s^2
My attempt at c)
Formula
a=f/m
a=75N/75kg
a=1 m/s^2
first of all I want to thank anyone that gives their time and effort to help me do this homework that is due very soon. I don’t think I understand it very well and I am start to get really worried. Secondly, if you notice any problems, can you please show me how to do it? Id appreciate any help I can get. Thanks a ton people.
My attempt
Data:
F-250N
m-45kg
a-m/s^2
Formula:
F=ma
a=F/m
a=250N/45kg
a=5.555
a=5.6m/s^2
Q2: a 0.5kg mass on a horizontal frictional free table is accelerated by a force from a string passing over a pulley and attached to a mass of 1.5kg hanging vertically.
My attempt
Data:
m-0.5kg
hanging m-1.5kg
formula:
F=F1+F2
F=0.5kg+1.5kg=2.0kg
F=ma
F=2.0kg(9.80m/s^2)
F=19.6 rounded to 20N
My attempt at B)
Data:
F=19.6N
m=2kg
a=?m/s^2?
Formula:
F=ma
a=F/m
a=19.6N/2kg
a=9.8 rounded to 10m/s^2
Q3: A 1200kg truck is moving at 108km/h and stops within a distance of 91m
a)What is the acceleration?
My attempt
Data:
m-1200kg
Vi-108km/h--->converted to 30m/s
Vf-0
s-91m
Formula:
2as=Vf^2+Vi^2
a=Vi^2/2s
a=(30m/s)^2/2(91m)
a=900m^2/s^2/182m
a=-4.9m/s^2(negative because it decelerated)
My attempt at part B)What is the coefficient of friction?
Formula:
Ff=uFn
u=Ff/Fn
u=4.9m/s^2/1200kg
u=0.00408
Q4: you are pulling a 3.0slug crate and a sliding friction is known to be 55lb. what is the acceleration o the crate when the pulling force is?
a)55lb, b)75lb and c)105lb
My attempt at a)
Date:
m: 3.0Slug
F:55lb
a:?m/s^2?
Formula:
F=ma
a=F/m
a=55lb/3.0slug
a=18ft/s^2
My attempt at part b)
Data:
m: 3.0slug
F: 75lb
a: ??
formula:
F=ma
a=F/m
a=75lb/3.0slug
a=25ft/s^2
My attempt at part c)
Data:
m: 3.0slug
F:105lb
a-??
Formula:
F=ma
a=F/m
a=105lb/3.0slug
a=35ft/s^2
Q5: During a training exercise, Brian who weighs 75kg skydives and parachutes from a stationary helicopter. What is the acceleration when the air drag is a)500N, b)1500N, and c)Equal to his weight
My attempt at a)
Data:
Fw:75kg
g:-9.80m/s^2
m: 500N
a=?
Formula:
F=ma
a=F/m
a=500N/75kg
a=6.66m/s^2
My attempt at b)
Formula:
a=F/m
a=1500N/75kg
a=20m/s^2
My attempt at c)
Formula
a=f/m
a=75N/75kg
a=1 m/s^2
first of all I want to thank anyone that gives their time and effort to help me do this homework that is due very soon. I don’t think I understand it very well and I am start to get really worried. Secondly, if you notice any problems, can you please show me how to do it? Id appreciate any help I can get. Thanks a ton people.