Semester Exam Review Physics

Which one of Newton's laws applies to the image?

• An object in motion stays in motion

• For every action there is an opposite reaction

• F=ma

Answer explanation

Once the apple is in motion [falling from the tree, it will stay in motion]. This is called inertia.

What are the units for velocity and speed?

• m/s

• seconds

• meters

Looking at the graph, this means that the object is...

• going backwards

• going forwards

• at rest

Tags

NGSS.MS-PS3-1

What is the velocity/speed here?

v=d/t

• 1 m/s

• 7 m/s

• 14 m/s

• 10 m/s

Answer explanation

v=d/t

pick any point on the graph

look at position [distance in meters] and divide that by the time in seconds

ex. 40/4 = 10 m/s

Tags

NGSS.MS-PS3-1

A bicyclist hits the bottom of a hill going 23.3 m/s.  If he had been traveling at 14.0 m/s BEFORE accelerating, Calculate his acceleration if he took 5.4 seconds to go down the hill.

[use equation from pic]

Answer explanation

a = (23.3-14)/5.4

a=1.72

Tags

NGSS.HS-PS2-1

A man runs 5600 m South in 1450 sec and then turns and runs 10,000 m North in 1950 sec.  Determine the distance.

• 15,600 m

• 19,450 m

• 1,650 m

• 20,000 m

Answer explanation

5600 + 10,000 = 15,600 m

A man runs 5600 m South in 1450 sec and then turns and runs 10,000 m North in 1950 sec.  Determine the displacement.

[displacement = larger distance - smaller distance]

[Remember, displacement entails direction]

• 8,400 m

• 4,400 m

Answer explanation

10,000 - 5600 = 4400

A man runs 5600 m South in 1450 sec and then turns and runs 10,000 m North in 1950 sec.  Determine the speed.

• 2.85 m/s

• 4.59 m/s

• 3.1 m/s

Answer explanation

s = d / t

*if there are multiple times, you add them

s = 15,600 / 3400

s = 4.59 m/s

A man runs 5600 m South in 1450 sec and then turns and runs 10,000 m North in 1950 sec.  Determine the velocity.

[v = displacement / time]

• 1.29 m/s

• 3.1 m/s

• .6 m/s

Answer explanation

v=4,400 / 3400

v=1.29 m/s

A car is traveling at a speed of 30 mph when it enters a gentle curve, allowing the car to make the curve while maintaining the speed of 30 mph.  If the car IS NOT changing speed WHY IS THE CAR SAID TO BE ACCELERATING?

• travelling at 30 mps

• change in direction

• maintaining 30 mph

Answer explanation

acceleration can mean:

-changing direction

-slowing down

-speeding up

Tags

NGSS.HS-PS2-1