Free Fall - Vectors - Projectile Motion

FREEFALL

What happens to the velocity of an object as it falls?

• speeds up

• slows down

• stays the same

• becomes zero

Answer explanation

The object is falling which means it has negative velocity.

Earth's gravitational force causes objects to accelerate at -9.81 m/s2.

Because velocity is negative and acceleration is negative, the object will speed up as it falls.

Tags

NGSS.HS-PS2-1

HORIZONTAL PROJECTILE MOTION

If an ball is LAUNCHED horizontally of a cliff, which values is NOT CORRECT?

Tags

NGSS.HS-PS2-4

NGSS.HS-PS2-2

FREEFALL

If a ball is thrown vertically in the air and falls back to the same spot after 2 seconds, which of the following is TRUE?

• The initial velocity of the ball is 0 m/s.

• The velocity of the ball at its highest point is 0 m/s.

• The velocity of the ball when reaches the person's hand again is 0 m/s.

Tags

NGSS.HS-PS2-1

FREEFALL

If an rock is DROPPED of a cliff, which value is constant during the free fall?

• displacement

• acceleration 

• velocity

• time

Tags

NGSS.HS-PS2-1

VECTORS

If a drone is flying at 15 m/s south and a headwind is blowing 5 m/s north, what is the resultant velocity of the drone?

• 20 m/s [S]

• 10 m/s [S]

• 10 m/s [N]

• 20 m/s [N]

Tags

NGSS.HS-PS2-1

VECTORS

Which of the following is TRUE about this vector?

• The horizontal component is 8 m [right].

• The vertical component is 7 m [up]

• The resultant vector magnitude is 7.21 m.

Answer explanation

X component = count it

y component = count it

Resultant magnitude use a² + b² = c²

Resultant direction use tan^-1

VECTORS

A person is trying to swim across a river that is flowing 9 m/s [E]. If the person is swimming at 1.5 m/s [N], what is the angle he is moving across the river?

Answer explanation

Resultant direction use tan^-1

Tags

NGSS.HS-PS2-1

VECTORS

A person is trying to swim across a river that is flowing 9 m/s [E]. If the person is swimming at 1.5 m/s [N], what is the person's resultant velocity?

(HINT: Find the magnitude of the resultant)

• 83.25 m/s

• 9.12 m/s 

•  13.5 m.s

•  8.87 m/s

Answer explanation

Resultant magnitude use a² + b² = c²

VECTORS

A giant slide at a carnival is 42.7 meters long and rises at a 25.4^o above the ground. How high do riders have to climb up to reach the top of the slide?

(HINT: Find the vertical component)

• 18.3 meters

• 38.6 meters

• 20.3 meters

• 17.2 meters

Answer explanation

You are given the resultant magnitude and direction.

Find the y component using sine or cosine of the angle.

VECTORS

A giant slide at a carnival is 42.7 meters long and rises at a 25.4^o above the ground. How far away from the stairs do the riders end up after sliding down?

(HINT: Find the horizontal component)

• 18.3 meters

• 38.6 meters

• 20.3 meters

• 17.2 meters

Answer explanation

You are given the resultant magnitude and direction.

Find the x component using sine or cosine of the angle.