# Worksheet: Potential Energy

Q1:

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. Take .

• A
28 420
J
• B56.84 J
• C28.42 J
• D
56 840
J

Q2:

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

Q3:

A body of mass 4 kg had a gravitational potential energy of 2 136.4 joules relative to the ground. Determine its height. Consider the acceleration due to gravity to be .

Q4:

A body of mass 3 kg had a gravitational potential energy of 1 528.8 joules relative to the ground. Determine its height. Consider the acceleration due to gravity to be .

Q5:

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

Q6:

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/s2.

• A
3 606.4
joules
• B
11 901.12
joules
• C
2 975.28
joules
• D
1 214.4
joules

Q7:

A helicopter of mass 2 630 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

Q8:

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
3 567.2
joules
• B30.89 joules
• C
3 089.29
joules
• D35.67 joules

Q9:

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
3 528
joules
• B17.64 joules
• C
1 764
joules
• D35.28 joules

Q10:

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 .

Q11:

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 .

Q12:

A ball of mass 334 g was projected vertically upwards 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 ball’s gravitational potential energy as it moved from to .

Q13:

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

• A52 erg
• B erg
• C202 erg
• D erg

Q14:

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

• A42 erg
• B102 erg
• C erg
• D erg

Q15:

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

• A1
• B
• C
• D6

Q16:

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

• A
• B
• C11
• D6

Q17:

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