**Q2: **

The force exerted by the Moon’s gravity at its surface is six times smaller than the force exerted by the Earth’s gravity at its surface. The weight of an astronaut plus his space suit on the Moon is 250 N.

How much does the suited astronaut weigh on Earth?

- A N
- B N
- C N
- D N
- E N

What is the mass of the suited astronaut on the Moon?

What is the mass of the suited astronaut on Earth?

**Q3: **

The mass of a particle is 15.0 kg.

What is its weight on Earth?

On the Moon, the acceleration produced by gravity is 1.63 m/s^{2}.
What is its weight of the particle on the Moon?

What is its mass on the Moon?

What is its weight in outer space far from any celestial body?

What is its mass at this point?

**Q4: **

Calculate the force a 70.0 kg high jumper must exert on the ground to produce an upward acceleration 4.00 times the acceleration due to gravity.

**Q5: **

A service elevator carries a load of garbage with a mass of 24.4 kg. the elevator accelerates vertically downward at 1.8 m/s^{2}. What is the magnitude of the force the garbage exerts on the floor of the elevator?

**Q6: **

Astronauts in orbit are apparently weightless. This
means that a clever method of measuring the mass of
astronauts is needed to monitor their mass gains or losses,
and adjust their diet. One way to do this is to exert a
known force on an astronaut and measure the acceleration
produced. Suppose a net external force of 50.0 N is exerted,
and an astronaut’s acceleration is measured to be
0.893 m/s^{2}. Calculate her mass.

**Q7: **

A uniformly cylindrical tube that is open at both ends has a diameter of 16 cm. Two spheres are at rest inside the tube, as shown in the accompanying diagram. The diameters of the spheres are 8 cm and 12 cm respectively and the spheres weigh 10 N and 30 N respectively. Calculate the minimum weight of the tube for the system of the tube and spheres to be in equilibrium.