Review of Projectile Motion, Mass & Weight

What is the weight of a 50 kg object near Earth? Ans. 500 N

What is the mass of a 5 kg rock on the Earth? Ans. 5 kg

What is the weight of a 10 kg rock on the Moon? (g = 1.7 m/s2) Ans. 17 N

What is the acceleration? 1 2 3 4 5 6 7 8 10 20 30 40 50 60 70 80 Velocity (m/s) Time (s) Ans. 20 m/s2

If the object has a mass of 2 kg, what is its weight? 1 2 3 4 5 6 7 8 10 20 30 40 50 60 70 80 Velocity (m/s) Time (s) Ans. 40 N

What is the displacement for the first 5 seconds? 1 2 3 4 5 6 7 8 10 20 30 40 50 60 70 80 velocity (m/s) Time (s) Ans. 75 m

A man throws a ball vertically upward A man throws a ball vertically upward. What is its velocity at its highest point? Ans. zero

A man throws a ball vertically upward A man throws a ball vertically upward. What is its acceleration at its highest point? Ans. 10 m/s2 downward

A man throws a ball vertically upward with an initial speed of 25 m/s A man throws a ball vertically upward with an initial speed of 25 m/s. At what time does it return to his hand? Ans. 5 s

A man throws a ball vertically upward with an initial speed of 25 m/s A man throws a ball vertically upward with an initial speed of 25 m/s. How high does it go? Ans. 31.3 m

What is the displacement for the first 3 seconds? 1 2 3 4 5 6 7 8 10 20 30 40 50 60 70 80 Position (m) Time (s) Ans. 60 m

What is the acceleration? 1 2 3 4 5 6 7 8 10 20 30 40 50 60 70 80 Position (m) Time (s) Ans. zero

What is the weight? 45 kg Ans. 450 N on Earth

Planet X has an acceleration due to gravity of 0. 1 m/s2 Planet X has an acceleration due to gravity of 0.1 m/s2. Joe can jump 1 m vertically on Earth. How high can he jump on Planet X? Ans. 100 m

Planet X has an acceleration due to gravity of 0. 1 m/s2 Planet X has an acceleration due to gravity of 0.1 m/s2. Joe has a mass of 55 kg on Earth. What is his mass on Planet X? Ans. 55 kg

Joe can lift a mass of 136 kg on Earth. How much weight is he lifting? Ans. 1360 N

Planet X has an acceleration due to gravity of 0. 1 m/s2 Planet X has an acceleration due to gravity of 0.1 m/s2. Joe can lift a mass of 136 kg on Earth. How much mass can he lift on Planet X? Ans. 13600 kg

Planet X has an acceleration due to gravity of 0. 1 m/s2 Planet X has an acceleration due to gravity of 0.1 m/s2. Joe’s workout set of weights has a mass of 200 kg. What is the weight of the set on Planet X? Ans. 20 N

The next four slides deal with the same initial information.

What is the initial vertical velocity of the object? 30 m/s 50 Ans. 23 m/s

What is the time in the air from launch to landing at same height? 30 m/s 50 Ans. 4.6 s

What is the maximum height reached by the object? 30 m/s 50 Ans. 26.5 m

What is the range for this projectile? 30 m/s 50 Ans. 88.8 m

The following two slides are based on the same initial information.

What is time in air? 15 m/s y x 2 m Dx Ans. 0.63 s

What is Dx? 15 m/s y x 2 m Dx Ans. 9.5 m

The following three slides have the same initial information.

How long will it take boat to cross river? 6 km 12 km/h B 4 km/h Ans. ½ h

How far downstream will the boat drift? 6 km 12 km/h B 4 km/h Ans. 2 km

What is the velocity of the boat relative to the shore? 6 km 12 km/h B 4 km/h Ans. 12.6 km/h @ 18.4 SE