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A particle moves from position 3hati+2ha...

A particle moves from position `3hati+2hatj-6hatk` to `14hati+13hatj+9hatk` due to a force `vecF=(4hati+hatj+3hatk)`N. If the displacement is in centimeter then work done will be

A

1 J

B

2 J

C

3 J

D

2.5 J

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem step by step, we will follow these steps: ### Step 1: Identify the initial and final positions The initial position vector \( \vec{r_1} \) and the final position vector \( \vec{r_2} \) are given as: - \( \vec{r_1} = 3\hat{i} + 2\hat{j} - 6\hat{k} \) - \( \vec{r_2} = 14\hat{i} + 13\hat{j} + 9\hat{k} \) ### Step 2: Calculate the displacement vector \( \vec{D} \) The displacement vector \( \vec{D} \) can be calculated using the formula: \[ \vec{D} = \vec{r_2} - \vec{r_1} \] Substituting the values: \[ \vec{D} = (14\hat{i} + 13\hat{j} + 9\hat{k}) - (3\hat{i} + 2\hat{j} - 6\hat{k}) \] Now, perform the subtraction: \[ \vec{D} = (14 - 3)\hat{i} + (13 - 2)\hat{j} + (9 + 6)\hat{k} \] \[ \vec{D} = 11\hat{i} + 11\hat{j} + 15\hat{k} \] ### Step 3: Identify the force vector \( \vec{F} \) The force vector \( \vec{F} \) is given as: \[ \vec{F} = 4\hat{i} + \hat{j} + 3\hat{k} \] ### Step 4: Calculate the work done \( W \) The work done \( W \) is calculated using the dot product of the force vector and the displacement vector: \[ W = \vec{F} \cdot \vec{D} \] Substituting the values: \[ W = (4\hat{i} + \hat{j} + 3\hat{k}) \cdot (11\hat{i} + 11\hat{j} + 15\hat{k}) \] Calculating the dot product: \[ W = 4 \cdot 11 + 1 \cdot 11 + 3 \cdot 15 \] \[ W = 44 + 11 + 45 \] \[ W = 100 \text{ Joules} \] ### Step 5: Convert the work done to centimeters Since the displacement was given in centimeters, we need to convert the work done from Joules to the appropriate unit. Since \( 1 \text{ Joule} = 10^4 \text{ cm} \cdot \text{N} \), the work done remains: \[ W = 100 \text{ Joules} \] ### Final Answer The work done is \( 100 \text{ Joules} \). ---

To solve the problem step by step, we will follow these steps: ### Step 1: Identify the initial and final positions The initial position vector \( \vec{r_1} \) and the final position vector \( \vec{r_2} \) are given as: - \( \vec{r_1} = 3\hat{i} + 2\hat{j} - 6\hat{k} \) - \( \vec{r_2} = 14\hat{i} + 13\hat{j} + 9\hat{k} \) ### Step 2: Calculate the displacement vector \( \vec{D} \) ...
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Knowledge Check

  • A particle acted upon by constant forces 4hati +hatj- 4 hatk and 3hati + hatj - hatk is displacment from the point hati+ 2hatj+ hatk to point 5hati + 4hatj +hatk .Total work done by the forces in SI unit is :

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    B
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    A
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    B
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    C
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    D
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