355747
Starting at rest, a \(10\;kg\) object is acted upon by only one force as indicated in figure. Then the total work done by the force is
1 \(90\;J\)
2 \(125\,J\)
3 \(245\,J\)
4 \(490\,J\)
Explanation:
Using impulse-momentum theorem \(P_{f}=P_{i}+\int F d t\) \(P=m v=0+30(2)-10 \times 1\) \(P=m v=50\) \(\Rightarrow K E\) gained \(=\dfrac{P^{2}}{2 m}\) \( = \frac{{2500}}{{20}}\) \( = 125\;J.\)
PHXI06:WORK ENERGY AND POWER
355748
Assertion : Surface between the blocks \(A\) and \(B\) is rough, work done by friction on block \(B\) is always negative. Reason : Total work done by friction on both the blocks is always zero
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Frictional force always acts in backward direction on block B. So work done on B is negative. If there is a sliding between \(A\) and \(B\) then work done by friction on the system is non zero. So option (3) is correct.
PHXI06:WORK ENERGY AND POWER
355750
A block of mass 5 \(kg\) slides down a rough inclined surface. The angle of inclination is \(45^{\circ}\). The coefficient of sliding friction is 0.20 . When the block slides 10 \(cm\) , the work done on the block by force of friction is
355751
A particle is displaced from a position \((2 \hat{i}-\hat{j}+\hat{k})\) another position \((3 \hat{i}+2 \hat{j}-2 \hat{k})\) under the action of force \((2 \hat{i}+\hat{j}-\hat{k})\). The work done by the force in an arbitrary unit is
1 8
2 10
3 12
4 16
Explanation:
Work done, \(W=F \cdot r\) \( = (2\hat i + \hat j - \hat k) \cdot [(3\hat i + 2\hat j - 2\hat k)\) \( - (2\hat i - \hat j + \hat k)]({\rm{ given }})\) \( = (2\hat i + \hat j - \hat k) \cdot (\hat i + 3\hat j - 3\hat k)\) \(W = 2 + 3 + 3 = 8{\rm{ unit }}\)
PHXI06:WORK ENERGY AND POWER
355752
The work done in pulling up a block of wood weighing 2 \(kN\) for a length of 10 \(m\) on a smooth plane inclined at an angle of \(15^{\circ}\) with the horizontal is \(\left[\sin 15^{\circ}=0.2588\right]\)
355747
Starting at rest, a \(10\;kg\) object is acted upon by only one force as indicated in figure. Then the total work done by the force is
1 \(90\;J\)
2 \(125\,J\)
3 \(245\,J\)
4 \(490\,J\)
Explanation:
Using impulse-momentum theorem \(P_{f}=P_{i}+\int F d t\) \(P=m v=0+30(2)-10 \times 1\) \(P=m v=50\) \(\Rightarrow K E\) gained \(=\dfrac{P^{2}}{2 m}\) \( = \frac{{2500}}{{20}}\) \( = 125\;J.\)
PHXI06:WORK ENERGY AND POWER
355748
Assertion : Surface between the blocks \(A\) and \(B\) is rough, work done by friction on block \(B\) is always negative. Reason : Total work done by friction on both the blocks is always zero
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Frictional force always acts in backward direction on block B. So work done on B is negative. If there is a sliding between \(A\) and \(B\) then work done by friction on the system is non zero. So option (3) is correct.
PHXI06:WORK ENERGY AND POWER
355750
A block of mass 5 \(kg\) slides down a rough inclined surface. The angle of inclination is \(45^{\circ}\). The coefficient of sliding friction is 0.20 . When the block slides 10 \(cm\) , the work done on the block by force of friction is
355751
A particle is displaced from a position \((2 \hat{i}-\hat{j}+\hat{k})\) another position \((3 \hat{i}+2 \hat{j}-2 \hat{k})\) under the action of force \((2 \hat{i}+\hat{j}-\hat{k})\). The work done by the force in an arbitrary unit is
1 8
2 10
3 12
4 16
Explanation:
Work done, \(W=F \cdot r\) \( = (2\hat i + \hat j - \hat k) \cdot [(3\hat i + 2\hat j - 2\hat k)\) \( - (2\hat i - \hat j + \hat k)]({\rm{ given }})\) \( = (2\hat i + \hat j - \hat k) \cdot (\hat i + 3\hat j - 3\hat k)\) \(W = 2 + 3 + 3 = 8{\rm{ unit }}\)
PHXI06:WORK ENERGY AND POWER
355752
The work done in pulling up a block of wood weighing 2 \(kN\) for a length of 10 \(m\) on a smooth plane inclined at an angle of \(15^{\circ}\) with the horizontal is \(\left[\sin 15^{\circ}=0.2588\right]\)
355747
Starting at rest, a \(10\;kg\) object is acted upon by only one force as indicated in figure. Then the total work done by the force is
1 \(90\;J\)
2 \(125\,J\)
3 \(245\,J\)
4 \(490\,J\)
Explanation:
Using impulse-momentum theorem \(P_{f}=P_{i}+\int F d t\) \(P=m v=0+30(2)-10 \times 1\) \(P=m v=50\) \(\Rightarrow K E\) gained \(=\dfrac{P^{2}}{2 m}\) \( = \frac{{2500}}{{20}}\) \( = 125\;J.\)
PHXI06:WORK ENERGY AND POWER
355748
Assertion : Surface between the blocks \(A\) and \(B\) is rough, work done by friction on block \(B\) is always negative. Reason : Total work done by friction on both the blocks is always zero
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Frictional force always acts in backward direction on block B. So work done on B is negative. If there is a sliding between \(A\) and \(B\) then work done by friction on the system is non zero. So option (3) is correct.
PHXI06:WORK ENERGY AND POWER
355750
A block of mass 5 \(kg\) slides down a rough inclined surface. The angle of inclination is \(45^{\circ}\). The coefficient of sliding friction is 0.20 . When the block slides 10 \(cm\) , the work done on the block by force of friction is
355751
A particle is displaced from a position \((2 \hat{i}-\hat{j}+\hat{k})\) another position \((3 \hat{i}+2 \hat{j}-2 \hat{k})\) under the action of force \((2 \hat{i}+\hat{j}-\hat{k})\). The work done by the force in an arbitrary unit is
1 8
2 10
3 12
4 16
Explanation:
Work done, \(W=F \cdot r\) \( = (2\hat i + \hat j - \hat k) \cdot [(3\hat i + 2\hat j - 2\hat k)\) \( - (2\hat i - \hat j + \hat k)]({\rm{ given }})\) \( = (2\hat i + \hat j - \hat k) \cdot (\hat i + 3\hat j - 3\hat k)\) \(W = 2 + 3 + 3 = 8{\rm{ unit }}\)
PHXI06:WORK ENERGY AND POWER
355752
The work done in pulling up a block of wood weighing 2 \(kN\) for a length of 10 \(m\) on a smooth plane inclined at an angle of \(15^{\circ}\) with the horizontal is \(\left[\sin 15^{\circ}=0.2588\right]\)
355747
Starting at rest, a \(10\;kg\) object is acted upon by only one force as indicated in figure. Then the total work done by the force is
1 \(90\;J\)
2 \(125\,J\)
3 \(245\,J\)
4 \(490\,J\)
Explanation:
Using impulse-momentum theorem \(P_{f}=P_{i}+\int F d t\) \(P=m v=0+30(2)-10 \times 1\) \(P=m v=50\) \(\Rightarrow K E\) gained \(=\dfrac{P^{2}}{2 m}\) \( = \frac{{2500}}{{20}}\) \( = 125\;J.\)
PHXI06:WORK ENERGY AND POWER
355748
Assertion : Surface between the blocks \(A\) and \(B\) is rough, work done by friction on block \(B\) is always negative. Reason : Total work done by friction on both the blocks is always zero
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Frictional force always acts in backward direction on block B. So work done on B is negative. If there is a sliding between \(A\) and \(B\) then work done by friction on the system is non zero. So option (3) is correct.
PHXI06:WORK ENERGY AND POWER
355750
A block of mass 5 \(kg\) slides down a rough inclined surface. The angle of inclination is \(45^{\circ}\). The coefficient of sliding friction is 0.20 . When the block slides 10 \(cm\) , the work done on the block by force of friction is
355751
A particle is displaced from a position \((2 \hat{i}-\hat{j}+\hat{k})\) another position \((3 \hat{i}+2 \hat{j}-2 \hat{k})\) under the action of force \((2 \hat{i}+\hat{j}-\hat{k})\). The work done by the force in an arbitrary unit is
1 8
2 10
3 12
4 16
Explanation:
Work done, \(W=F \cdot r\) \( = (2\hat i + \hat j - \hat k) \cdot [(3\hat i + 2\hat j - 2\hat k)\) \( - (2\hat i - \hat j + \hat k)]({\rm{ given }})\) \( = (2\hat i + \hat j - \hat k) \cdot (\hat i + 3\hat j - 3\hat k)\) \(W = 2 + 3 + 3 = 8{\rm{ unit }}\)
PHXI06:WORK ENERGY AND POWER
355752
The work done in pulling up a block of wood weighing 2 \(kN\) for a length of 10 \(m\) on a smooth plane inclined at an angle of \(15^{\circ}\) with the horizontal is \(\left[\sin 15^{\circ}=0.2588\right]\)
355747
Starting at rest, a \(10\;kg\) object is acted upon by only one force as indicated in figure. Then the total work done by the force is
1 \(90\;J\)
2 \(125\,J\)
3 \(245\,J\)
4 \(490\,J\)
Explanation:
Using impulse-momentum theorem \(P_{f}=P_{i}+\int F d t\) \(P=m v=0+30(2)-10 \times 1\) \(P=m v=50\) \(\Rightarrow K E\) gained \(=\dfrac{P^{2}}{2 m}\) \( = \frac{{2500}}{{20}}\) \( = 125\;J.\)
PHXI06:WORK ENERGY AND POWER
355748
Assertion : Surface between the blocks \(A\) and \(B\) is rough, work done by friction on block \(B\) is always negative. Reason : Total work done by friction on both the blocks is always zero
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but reason is correct.
Explanation:
Frictional force always acts in backward direction on block B. So work done on B is negative. If there is a sliding between \(A\) and \(B\) then work done by friction on the system is non zero. So option (3) is correct.
PHXI06:WORK ENERGY AND POWER
355750
A block of mass 5 \(kg\) slides down a rough inclined surface. The angle of inclination is \(45^{\circ}\). The coefficient of sliding friction is 0.20 . When the block slides 10 \(cm\) , the work done on the block by force of friction is
355751
A particle is displaced from a position \((2 \hat{i}-\hat{j}+\hat{k})\) another position \((3 \hat{i}+2 \hat{j}-2 \hat{k})\) under the action of force \((2 \hat{i}+\hat{j}-\hat{k})\). The work done by the force in an arbitrary unit is
1 8
2 10
3 12
4 16
Explanation:
Work done, \(W=F \cdot r\) \( = (2\hat i + \hat j - \hat k) \cdot [(3\hat i + 2\hat j - 2\hat k)\) \( - (2\hat i - \hat j + \hat k)]({\rm{ given }})\) \( = (2\hat i + \hat j - \hat k) \cdot (\hat i + 3\hat j - 3\hat k)\) \(W = 2 + 3 + 3 = 8{\rm{ unit }}\)
PHXI06:WORK ENERGY AND POWER
355752
The work done in pulling up a block of wood weighing 2 \(kN\) for a length of 10 \(m\) on a smooth plane inclined at an angle of \(15^{\circ}\) with the horizontal is \(\left[\sin 15^{\circ}=0.2588\right]\)
