Units 3 & 4

How many forces act in an object subject to free fall?

• 1

• 2

• 3

• 4

If air resitance and friction are negligible, then all the objects fall toward the centre of the Earth __________.

• with the same velocity, independent of their mass

• with the same acceleration, independent of their mass

• with the same velocity, dependent of their mass

• with the same acceleration, dependent of their mass

Air resistance canc ause a slower fall in __________.

• objects with smaller masses

• objects with bigger masses

• objects with smaller volumes

• objects with bigger volumes

You drop a ball from the top of a building like the one in the picture. Calculate the time for that object to reach the floor. Give your answer in seconds with two decimals, rounding up. You must send me a picture of your procedures.

You throw a ball up like the picture shows. Calculate the maximum height that it can reach. Give your answer in metres with one decimal, rounding up. You must send me a picture of your procedures.

Calculate the total time of flight of the object that is thrown in the image. Give your answer in seconds with two decimals, rounding up. You must send me a picture of your procedures.

Two charges are separated a distance "r". Both have the same mass and the same charge. Which of the following will be the smallest between them?

• Electromagnetic repulsion force

• Electromagnetic attraction force

• Gravitational attraction force

• Strong nuclear force

Calculate the force that the charge Q2 feels because of the charge Q3. Give your answer with one decimal. Consider that the Coulumbs constant = 9 x 10⁹ and that micro(μ) means x10‐⁶. You must send me a picture of your procedures.

Calculate the net force that the charge Q1 feels. Give your answer with three decimals. Consider that the Coulumbs constant = 9 x 10⁹ and that micro(μ) means x10‐⁶.

Two astral bodies feel a gravitational attraction force of 1.0672 N. Estimate the distance between these two bodies if the bodies have masses of 200,000 kg and 5,000,000 kg. Consider that the gravitational constant = 6.67 x 10-¹¹