Physics Answers

A person pulls on a spring, stretching it 20 cm, which requires a maximum force of

800 N. Find the potential energy stored in the spring when it is stretched 20 cm and

compressed 5 cm.

Inductor as a component in transformer used 10 k resistor. Calculate the maximum

voltage that can be applied to achieve a power of 0.15W

An open cylindrical tank of 20 m high and 30 m in diameter is filled with water. Given

that the atmospheric pressure,

P

=1.013 × 105 N/m2

.

i) Determine the water pressure on the bottom of the tank.

ii) Calculate the total force on the bottom of tank.

A person pulls on a spring, stretching it 15 cm, which requires a maximum force of 750 N. Find the potential energy stored in the spring when it is stretched by 15 cm and compressed by 5 cm.

A 1-kg metal sample is heated to 90°C and then dropped into an insulated container containing 200 mL of water at 25°C. When thermal equilibrium is reached, the temperature of water rose to 40°C. What is the final temperature of the metal sample?

• An object with a mass of 3.50 kg moves in a straight line on a frictionless horizontal surface with a speed of 2.0 m/s. Find the kinetic energy and the net work done on the object to make it reach this speed if it started from rest.

A hydraulic lift has input and output pistons with diameters of 0.12 m and 0.48 m, respectively. If a force of 275 N is exerted at the input piston, calculate the maximum mass that can be lifted by the output piston.

A cylindrical water tank of diameter 15.0 m and height of 5.5 m contains 7.0 m3 of water. Calculate the force on the base of the tank. 

An elevator carrying 10 passengers through a height of 10 m from the ground has a mass of 2000 kg. Calculate the power required by the motor to lift the elevator if the time taken to lift the elevator to that height is 1 minute. 

An object with a mass of 3.50 kg moves in a straight line on a frictionless horizontal surface with a speed of 2.0 m/s. Find the kinetic energy and the net work done on the object to make it reach this speed if it started from rest.