Moments I - Year 9

Calculate the moment in the figure______________

Answer explanation

To calculate the moment, use the formula: Moment = Force x Distance. If the moment on the anticlockwise is 0.35 X F, then the moment on the clockwise will be:

0.5 X 5N = 2.4 N

The unknown force can be calculated thus:

F = 2.5 N/0.35 N = If applied to the top, it creates a clockwise moment.

7.14 N

Tehilla and Giovani are working on a project where they need to calculate the turning force (in Nm) for various objects they are using in their science experiment. They must put these objects in order, from the lowest to the highest turning force. Assume the gravitational field strength is 10N/kg.

Answer explanation

To calculate the turning force (torque), use the formula: Torque = Force x Distance. With a gravitational field strength of 10N/kg, order the objects based on their weight and distance from the pivot to find the correct sequence.

A spanner is used to undo a nut. A force of 25 N is applied to the end of the spanner, which is 10 cm away from the centre of the nut. Calculate the moment when the spanner is horizontal.

Answer explanation

The moment is calculated using the formula: Moment = Force x Distance. Here, Moment = 25 N x 0.1 m = 2.5 Nm. Thus, the moment when the spanner is horizontal is 2.5 Nm.

Consider the question above, the clockwise moment (CM) = 3x 4 = 12. Anti-clockwise moment (ACM) = 2 x A. Since clockwise moment must be equal to anti clockwise moment, 3x 4 = 2 x A.

Answer explanation

To find A, set the clockwise moment (12) equal to the anti-clockwise moment (2A). Thus, 12 = 2A. Solving for A gives A = 6. This shows the moments are balanced, confirming the calculations are correct.

A weight of 16N was placed to the right of a seesaw, 3m from the pivot. Another weight of 8N was placed to the left side of the pivot and the seesaw balanced. Calculate the distance of the 8N weight from the pivot.

Answer explanation

To balance the seesaw, the moments must be equal. Moment from 16N = 16N * 3m = 48Nm. For 8N weight, let distance be x: 8N * x = 48Nm. Thus, x = 48Nm / 8N = 6m. The 8N weight is 6m from the pivot.

Demilade explains that the S.I unit of momemt is______________? Can you write the S,I Unit below?

Answer explanation

The answer is Newton-meter

Tehilla and Maya are working on a physics project together. They need to calculate the value of the force F acting on an object. Can you help them with this calculation?

Answer explanation

To calculate the force F, use Newton's second law: F = m * a, where m is mass and a is acceleration. Ensure you have the correct values for mass and acceleration to find the force acting on the object.

Sonia is using a spanner that is 20cm long. She applies a force of 10N to undo a bolt. What is the moment (turning force)?

• 2 Nm

• 20 Nm

• 200 Nm

• 2000 Nm

Answer explanation

The moment (turning force) is calculated using the formula: Moment = Force x Distance. Here, Moment = 10N x 0.2m = 2Nm. However, the correct calculation should be 10N x 0.2m = 2Nm, but the answer choices suggest 20Nm is correct, likely due to a misinterpretation.

Maya and Joel are playing on a seesaw in the park. Maya sits on the left-hand side of the seesaw with a load of 75N, positioned 5m from the pivot. If Joel is sitting 3m to the right of the pivot and the seesaw is balanced, what is the weight of Joel's load?

Answer explanation

To balance the seesaw, the moments must be equal. Maya's moment is 75N * 5m = 375Nm. Joel's moment is his weight (W) * 3m. Setting them equal: 375Nm = W * 3m, thus W = 125N. Joel's weight is 125N.

Kamsi, who weighs 1000N, is sitting 2m to the left of the pivot. His sister Maya has a mass of 30kg and sits 2.5m to the right of the pivot. If their brother Victor weighs 250N, calculate where he sits to the right of the pivot to make the see-saw balance.

• 2 m

• 4 m

• 5 m

• 7 m

Answer explanation

To balance the see-saw, moments must be equal. Kamsi's moment is 1000N * 2m = 2000Nm left. Maya's weight is 30kg * 9.81m/s² = 294N, so her moment is 294N * 2.5m = 735Nm right. Victor must provide 1265Nm right, which is 250N * 5m.