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momentum

A motor vehicle having a mass of 1.8t is at rest on an incline of 1 in 12 (sine) when the brakes are released. The vehicle travels 30m down the incline against a constant frictional resistance to motion of 200N/t and reaches the bottom of the slope.
(a) Using the principle of conservation of energy, calculate the velocity of the vehicle at the bottom of the incline.
(b) Using an alternative method that does not involve a consideration of energy, calculate the velocity of the vehicle at the bottom of the incline.
(c) Discuss the merits of the two methods you have used for parts (a) and (b) of this question. Justify the use of an energy method for these types of problems.

please help.
Reply 1
Increase in KE = Loss in GPE - Work Done by Friction
Reply 2
Original post by swinroy
Increase in KE = Loss in GPE - Work Done by Friction

which part of the question is that for and what do I write for part c. hope you can help. thanks.
Reply 3
Original post by raffay13
which part of the question is that for and what do I write for part c. hope you can help. thanks.

KE stands for Kinetic Energy so perhaps PART a ?????????
Part b is a method whereby you find the resultant force down the plane then use Newton’s 2 nd law to find acceleration down the plane. Then use SUVAT to find speed
Part c is trying to make the student realise that Energy method only requires ONE equation and takes Less time to calculate
Reply 4
Original post by Swinroy2
KE stands for Kinetic Energy so perhaps PART a ?????????
Part b is a method whereby you find the resultant force down the plane then use Newton’s 2 nd law to find acceleration down the plane. Then use SUVAT to find speed
Part c is trying to make the student realise that Energy method only requires ONE equation and takes Less time to calculate

thanks bro. can you please let me know what you got as answers for part a and b and then I can compare it to what I got If you can. sorry if I am disturbing you.
Reply 5
Original post by raffay13
which part of the question is that for and what do I write for part c. hope you can help. thanks.

900 (v- squared) = 1800g30(1/12) - 200(1.8)(30)
Reply 6
Original post by swinroy
900 (v- squared) = 1800g30(1/12) - 200(1.8)(30)

which question part is this for
Reply 7
Original post by raffay13
which question part is this for

Omg ...I give up
Please think it through
Reply 8
A motor vehicle having a mass of 1.8t is at rest on an incline of 1 in 12 (sine) when the brakes are released. The vehicle travels 30m down the incline against a constant frictional resistance to motion of 200N/t and reaches the bottom of the slope.
(a) Using the principle of conservation of energy, calculate the velocity of the vehicle at the bottom of the incline.
(b) Using an alternative method that does not involve a consideration of energy, calculate the velocity of the vehicle at the bottom of the incline.
(c) Discuss the merits of the two methods you have used for parts (a) and (b) of this question. Justify the use of an energy method for these types of problems.
Original post by raffay13
A motor vehicle having a mass of 1.8t is at rest on an incline of 1 in 12 (sine) when the brakes are released. The vehicle travels 30m down the incline against a constant frictional resistance to motion of 200N/t and reaches the bottom of the slope.
(a) Using the principle of conservation of energy, calculate the velocity of the vehicle at the bottom of the incline.
(b) Using an alternative method that does not involve a consideration of energy, calculate the velocity of the vehicle at the bottom of the incline.
(c) Discuss the merits of the two methods you have used for parts (a) and (b) of this question. Justify the use of an energy method for these types of problems.

please help.

Hi, please shows some effort in thinking and attempting this question. At least, tell us what have you learnt or what are you learning when you are given this question.
Tell us what are your difficulties. :smile:
Reply 10
A motor vehicle having a mass of 1.8t is at rest on an incline of 1 in 12 (sine) when the brakes are released. The vehicle travels 30m down the incline against a constant frictional resistance to motion of 200N/t and reaches the bottom of the slope.
(a) Using the principle of conservation of energy, calculate the velocity of the vehicle at the bottom of the incline.
(b) Using an alternative method that does not involve a consideration of energy, calculate the velocity of the vehicle at the bottom of the incline.
(c) Discuss the merits of the two methods you have used for parts (a) and (b) of this question. Justify the use of an energy method for these types of problems.
Original post by raffay13
A motor vehicle having a mass of 1.8t is at rest on an incline of 1 in 12 (sine) when the brakes are released. The vehicle travels 30m down the incline against a constant frictional resistance to motion of 200N/t and reaches the bottom of the slope.
(a) Using the principle of conservation of energy, calculate the velocity of the vehicle at the bottom of the incline.
(b) Using an alternative method that does not involve a consideration of energy, calculate the velocity of the vehicle at the bottom of the incline.
(c) Discuss the merits of the two methods you have used for parts (a) and (b) of this question. Justify the use of an energy method for these types of problems.

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