00. Work done by Force and Power
Work, Energy and Power

148777 A force of $4 \mathrm{~N}$ acts on a $10 \mathrm{~kg}$ body initially at rest. Let $W_{1}$ is work done by force during 0 $\leq t \leq 1$ s. Likewise $W_{2}$ is the work done by force during $1 \mathrm{~s} \leq \mathrm{t} \leq 2 \mathrm{~s}$, where $\mathrm{t}$ is time in second. The ratio $\frac{W_{2}}{W_{1}}$ is

1 1
2 2
3 $\frac{1}{2}$
4 3
Work, Energy and Power

148778 A boy pushes a toy box $2.0 \mathrm{~m}$ along the floor by means of a force of $10 \mathrm{~N}$ directed downward at an angle of $60^{\circ}$ to the horizontal. The work done by the boy is

1 $6 \mathrm{~J}$
2 $8 \mathrm{~J}$
3 $10 \mathrm{~J}$
4 $12 \mathrm{~J}$
Work, Energy and Power

148779 A man pushes the wall and fails to displace it. He does

1 negative work
2 positive but not maximum work
3 no work at all
4 maximum work
Work, Energy and Power

148780 An automatic gun fires 360 bullets per minute with a speed of $360 \mathrm{~km} / \mathrm{h}$. If each bullet weight $20 \mathrm{~g}$, the power of the gun is

1 $75 \mathrm{~W}$
2 $150 \mathrm{~W}$
3 $300 \mathrm{~W}$
4 $600 \mathrm{~W}$
Work, Energy and Power

148781 A force $F=20+10 y$ acts on a particle in $y$ direction, where $F$ is in Newton and $y$ in meter. Work done by this force to move the particle from $\mathrm{y}=0$ to $\mathrm{y}=1 \mathrm{~m}$ is

1 $5 \mathrm{~J}$
2 $25 \mathrm{~J}$
3 $20 \mathrm{~J}$
4 $30 \mathrm{~J}$
Work, Energy and Power

148777 A force of $4 \mathrm{~N}$ acts on a $10 \mathrm{~kg}$ body initially at rest. Let $W_{1}$ is work done by force during 0 $\leq t \leq 1$ s. Likewise $W_{2}$ is the work done by force during $1 \mathrm{~s} \leq \mathrm{t} \leq 2 \mathrm{~s}$, where $\mathrm{t}$ is time in second. The ratio $\frac{W_{2}}{W_{1}}$ is

1 1
2 2
3 $\frac{1}{2}$
4 3
Work, Energy and Power

148778 A boy pushes a toy box $2.0 \mathrm{~m}$ along the floor by means of a force of $10 \mathrm{~N}$ directed downward at an angle of $60^{\circ}$ to the horizontal. The work done by the boy is

1 $6 \mathrm{~J}$
2 $8 \mathrm{~J}$
3 $10 \mathrm{~J}$
4 $12 \mathrm{~J}$
Work, Energy and Power

148779 A man pushes the wall and fails to displace it. He does

1 negative work
2 positive but not maximum work
3 no work at all
4 maximum work
Work, Energy and Power

148780 An automatic gun fires 360 bullets per minute with a speed of $360 \mathrm{~km} / \mathrm{h}$. If each bullet weight $20 \mathrm{~g}$, the power of the gun is

1 $75 \mathrm{~W}$
2 $150 \mathrm{~W}$
3 $300 \mathrm{~W}$
4 $600 \mathrm{~W}$
Work, Energy and Power

148781 A force $F=20+10 y$ acts on a particle in $y$ direction, where $F$ is in Newton and $y$ in meter. Work done by this force to move the particle from $\mathrm{y}=0$ to $\mathrm{y}=1 \mathrm{~m}$ is

1 $5 \mathrm{~J}$
2 $25 \mathrm{~J}$
3 $20 \mathrm{~J}$
4 $30 \mathrm{~J}$
Work, Energy and Power

148777 A force of $4 \mathrm{~N}$ acts on a $10 \mathrm{~kg}$ body initially at rest. Let $W_{1}$ is work done by force during 0 $\leq t \leq 1$ s. Likewise $W_{2}$ is the work done by force during $1 \mathrm{~s} \leq \mathrm{t} \leq 2 \mathrm{~s}$, where $\mathrm{t}$ is time in second. The ratio $\frac{W_{2}}{W_{1}}$ is

1 1
2 2
3 $\frac{1}{2}$
4 3
Work, Energy and Power

148778 A boy pushes a toy box $2.0 \mathrm{~m}$ along the floor by means of a force of $10 \mathrm{~N}$ directed downward at an angle of $60^{\circ}$ to the horizontal. The work done by the boy is

1 $6 \mathrm{~J}$
2 $8 \mathrm{~J}$
3 $10 \mathrm{~J}$
4 $12 \mathrm{~J}$
Work, Energy and Power

148779 A man pushes the wall and fails to displace it. He does

1 negative work
2 positive but not maximum work
3 no work at all
4 maximum work
Work, Energy and Power

148780 An automatic gun fires 360 bullets per minute with a speed of $360 \mathrm{~km} / \mathrm{h}$. If each bullet weight $20 \mathrm{~g}$, the power of the gun is

1 $75 \mathrm{~W}$
2 $150 \mathrm{~W}$
3 $300 \mathrm{~W}$
4 $600 \mathrm{~W}$
Work, Energy and Power

148781 A force $F=20+10 y$ acts on a particle in $y$ direction, where $F$ is in Newton and $y$ in meter. Work done by this force to move the particle from $\mathrm{y}=0$ to $\mathrm{y}=1 \mathrm{~m}$ is

1 $5 \mathrm{~J}$
2 $25 \mathrm{~J}$
3 $20 \mathrm{~J}$
4 $30 \mathrm{~J}$
Work, Energy and Power

148777 A force of $4 \mathrm{~N}$ acts on a $10 \mathrm{~kg}$ body initially at rest. Let $W_{1}$ is work done by force during 0 $\leq t \leq 1$ s. Likewise $W_{2}$ is the work done by force during $1 \mathrm{~s} \leq \mathrm{t} \leq 2 \mathrm{~s}$, where $\mathrm{t}$ is time in second. The ratio $\frac{W_{2}}{W_{1}}$ is

1 1
2 2
3 $\frac{1}{2}$
4 3
Work, Energy and Power

148778 A boy pushes a toy box $2.0 \mathrm{~m}$ along the floor by means of a force of $10 \mathrm{~N}$ directed downward at an angle of $60^{\circ}$ to the horizontal. The work done by the boy is

1 $6 \mathrm{~J}$
2 $8 \mathrm{~J}$
3 $10 \mathrm{~J}$
4 $12 \mathrm{~J}$
Work, Energy and Power

148779 A man pushes the wall and fails to displace it. He does

1 negative work
2 positive but not maximum work
3 no work at all
4 maximum work
Work, Energy and Power

148780 An automatic gun fires 360 bullets per minute with a speed of $360 \mathrm{~km} / \mathrm{h}$. If each bullet weight $20 \mathrm{~g}$, the power of the gun is

1 $75 \mathrm{~W}$
2 $150 \mathrm{~W}$
3 $300 \mathrm{~W}$
4 $600 \mathrm{~W}$
Work, Energy and Power

148781 A force $F=20+10 y$ acts on a particle in $y$ direction, where $F$ is in Newton and $y$ in meter. Work done by this force to move the particle from $\mathrm{y}=0$ to $\mathrm{y}=1 \mathrm{~m}$ is

1 $5 \mathrm{~J}$
2 $25 \mathrm{~J}$
3 $20 \mathrm{~J}$
4 $30 \mathrm{~J}$
Work, Energy and Power

148777 A force of $4 \mathrm{~N}$ acts on a $10 \mathrm{~kg}$ body initially at rest. Let $W_{1}$ is work done by force during 0 $\leq t \leq 1$ s. Likewise $W_{2}$ is the work done by force during $1 \mathrm{~s} \leq \mathrm{t} \leq 2 \mathrm{~s}$, where $\mathrm{t}$ is time in second. The ratio $\frac{W_{2}}{W_{1}}$ is

1 1
2 2
3 $\frac{1}{2}$
4 3
Work, Energy and Power

148778 A boy pushes a toy box $2.0 \mathrm{~m}$ along the floor by means of a force of $10 \mathrm{~N}$ directed downward at an angle of $60^{\circ}$ to the horizontal. The work done by the boy is

1 $6 \mathrm{~J}$
2 $8 \mathrm{~J}$
3 $10 \mathrm{~J}$
4 $12 \mathrm{~J}$
Work, Energy and Power

148779 A man pushes the wall and fails to displace it. He does

1 negative work
2 positive but not maximum work
3 no work at all
4 maximum work
Work, Energy and Power

148780 An automatic gun fires 360 bullets per minute with a speed of $360 \mathrm{~km} / \mathrm{h}$. If each bullet weight $20 \mathrm{~g}$, the power of the gun is

1 $75 \mathrm{~W}$
2 $150 \mathrm{~W}$
3 $300 \mathrm{~W}$
4 $600 \mathrm{~W}$
Work, Energy and Power

148781 A force $F=20+10 y$ acts on a particle in $y$ direction, where $F$ is in Newton and $y$ in meter. Work done by this force to move the particle from $\mathrm{y}=0$ to $\mathrm{y}=1 \mathrm{~m}$ is

1 $5 \mathrm{~J}$
2 $25 \mathrm{~J}$
3 $20 \mathrm{~J}$
4 $30 \mathrm{~J}$