**Q3: **

A crane lifts a body of mass 132 kg to a height of 20 m. Find the increase in the bodyβs gravitational potential energy. Consider the acceleration due to gravity .

**Q4: **

A crane lifts a body of mass 101 kg to a height of 6 m. Find the increase in the bodyβs gravitational potential energy. Consider the acceleration due to gravity .

**Q5: **

A particle is moving from point to point under the action of the force dynes. Determine the change in the particleβs potential energy, given that the displacement is in centimeters.

- A 202 erg
- B erg
- C 52 erg
- D erg

**Q6: **

A particle is moving from point to point under the action of the force dynes. Determine the change in the particleβs potential energy, given that the displacement is in centimeters.

- A erg
- B erg
- C 42 erg
- D 102 erg

**Q7: **

A body of mass 8 kg moved 238 cm up the line of greatest slope of a smooth plane inclined at to the horizontal. Calculate the increase in its gravitational potential energy. Take .

**Q8: **

A body of mass 7.5 kg is at a height of 14 cm above the ground. Determine the potential energy of the body relative to the ground, take .

- A ergs
- B ergs
- C ergs
- D ergs

**Q9: **

A body of mass 7 kg moved 52 cm up the line of greatest slope of a smooth plane inclined at to the horizontal. Find the increase in its gravitational potential energy. Take .

- A 3β089.29 joules
- B 35.67 joules
- C 3β567.2 joules
- D 30.89 joules

**Q10: **

A body of mass 3 kg moved 120 cm up the line of greatest slope of a smooth plane inclined at to the horizontal. Find the increase in its gravitational potential energy. Take .

- A 1β764 joules
- B 35.28 joules
- C 3β528 joules
- D 17.64 joules

**Q11: **

A body of mass 543 g is at a height of 22 m above the surface of the ground. Determine its gravitational potential energy relative to the ground, rounding your answer to two decimal places. Take .

- A 58.54 J
- B 117β070.80 J
- C 58β535.40 J
- D 117.07 J

**Q12: **

A body of mass 580 g is at a height of 10 m above the surface of the ground. Determine its gravitational potential energy relative to the ground, rounding your answer to two decimal places. Take .

- A 28.42 J
- B 56β840.00 J
- C 28β420.00 J
- D 56.84 J

**Q13: **

A helicopter of mass 3β830 kg descended vertically from a height of 370 m to a height of 280 m. Find its loss in gravitational potential energy. Consider the acceleration due to gravity to be .

- A J
- B J
- C J
- D J

**Q14: **

A helicopter of mass 2β630 kg descended vertically from a height of 250 m to a height of 150 m. Find its loss in gravitational potential energy. Consider the acceleration due to gravity to be .

- A J
- B J
- C J
- D J

**Q15: **

A ball of mass 317 g was projected vertically upward at 29 m/s from a point . It passed through a point , at 21 m/s, where is vertically above . Neglecting air resistance, use the work-energy principle to find the increase in the ballβs gravitational potential energy as it moved from to .

- A 126.8 joules
- B 203.2 joules
- C 406.39 joules
- D 63.4 joules

**Q16: **

A ball of mass 334 g was projected vertically upward at 22 m/s from a point . It passed through a point , at 18 m/s, where is vertically above . Neglecting air resistance, use the work-energy principle to find the increase in the ballβs gravitational potential energy as it moved from to .

- A 53.44 joules
- B 134.94 joules
- C 269.87 joules
- D 26.72 joules

**Q17: **

A body is moving in a straight line from point to point under the action of the force . Given that the change in the bodyβs potential energy is 2 joules and that the displacement is in meters, determine the value of the constant .

- A
- B6
- C1
- D

**Q18: **

A body is moving in a straight line from point to point under the action of the force . Given that the change in the bodyβs potential energy is joules and that the displacement is in meters, determine the value of the constant .

- A11
- B6
- C
- D

**Q19: **

A body is moving under the action of a constant force , where and are two perpendicular unit vectors. At time seconds, where , the bodyβs position vector relative to a fixed point is given by . Determine the change in the bodyβs potential energy in the first 9 seconds.

**Q20: **

A man of mass 92 kg
is going from the sixth floor to the tenth floor in an elevator.
Given that the height of each floor is 3.3 m, determine the gain in gravitational potential energy.
Consider the acceleration due to gravity to be 9.8 m/s^{2}.

- A 2β975.28 joules
- B 1β214.4 joules
- C 3β606.4 joules
- D 11β901.12 joules

**Q21: **

A person of mass 105 kg was hiking up a hill which was inclined to the horizontal at an angle whose sine is . Given that he covered a distance of 87 m, find the change in his gravitational potential energy. Take .