Force

1
Force Motion

• Problems

2
How far does a bicycle travel at a speed of 15
m/s for 15 seconds?
3
How far does a bicycle travel at a speed of 15
m/s for 15 seconds?

• D S x T
• D 15m/s / 15s
• D 1m

4
A swimmer swims 20 m in 40 s. What is the
swimmers average speed?
5
A swimmer swims 20 m in 40 s. What is the
swimmers average speed?

• S D/T
• S 20m/40s
• S 0.5m/s

6
What is the average speed (mph) for a car journey
of 120 miles that began at 09.30 and finished at
12.00 noon?
7
What is the average speed (mph) for a car journey
of 120 miles that began at 09.30 and finished at
12.00 noon?

• S D/T
• D 120
• T 2.5 hours (from 930 1200)
• S 120m / 2.5h
• S 48 mph

8
A person is traveling at 20 m/s in a car when the
car hits a tree. The person comes to a complete
stop in 0.4 seconds. What was the persons
acceleration?
9
A person is traveling at 20 m/s in a car when the
car hits a tree. The person comes to a complete
stop in 0.4 seconds. What was the persons
acceleration?

• a (0 m/s 20 m/s)/0.4 s 50 m/s2

10
You throw a ball to a friend. If the ball has a
mass of0.15kg and it accelerates at 20m/s, what
force did you exert on the ball.
11
You throw a ball to a friend. If the ball has a
mass of0.15kg and it accelerates at 20m/s, what
force did you exert on the ball.

• F m x a
• F 0.15 x 20 3N

12
You throw a 0.5 kg ball with a force of 10N.
What is the balls acceleration?
13
You throw a 0.5 kg ball with a force of 10N.
What is the balls acceleration?

• M 0.5
• F 10 N
• Acceleration a
• A F/m
• 10 N / 0.5 kg 20m/s2