# Isaac Physics - Moments Help?

Watch
Announcements
#1
I'll start off by saying that the hints for the questions do not help me one bit.

There's 2 questions that I've been stuck on for about a week

1) Shelf and brackets
A shelf of uniform density is supported by two brackets at a distance of 1/8 and 1/4 of the total length, L from each end respectively.

A) Find the ratio of the reaction forces from the brackets on the shelf. Express your answer in the form of a decimal less than 1 to three significant figures.

B) The rectangular shelf is now replaced with a uniform right-angled triangular shelf, as shown in the figure below. The centre of mass of a triangle lies at a point 1/3 of the perpendicular distance from the base to the tip.

https://isaacphysics.org/questions/s...?board=moments

2) Weight of a lorry

A haulage company wants to determine the weight of a lorry with four identical wheels, which is too large to stand with all four wheels on a single weighing platform.The lorry is placed so that the two front wheels are on one weighing platform and the two back wheels on another; the masses recorded are 1350kg and 1450kg respectively. The axles are 3.00m apart and at the same height

A) Find the mass of the lorry (2800kg) - answered

B) Find the distance of the centre of mass from the front axle.

C) What additional mass m would have to be placed 50.0cm in front of the front axle to make the weights borne by the axles equal? (75kg) - answered

https://isaacphysics.org/questions/w...?board=momentsHonestly i just need help. I can't find a way to solve these questions
0
2 years ago
#2
How'd you do the answer part C for the lorry question?
0
X

new posts
Back
to top
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### Poll

Join the discussion

#### Feeling behind at school/college? What is the best thing your teachers could to help you catch up?

Extra compulsory independent learning activities (eg, homework tasks) (18)
7.38%
Run extra compulsory lessons or workshops (37)
15.16%
Focus on making the normal lesson time with them as high quality as possible (44)
18.03%
Focus on making the normal learning resources as high quality/accessible as possible (35)
14.34%
Provide extra optional activities, lessons and/or workshops (63)
25.82%
Assess students, decide who needs extra support and focus on these students (47)
19.26%