Equations of Motion

The head of a snake can accelerate at 50 m/s2when it strikes. The snake’s head starts from rest and
accelerates constantly until it strikes a victim that is 0.5 m away.
a) How fast is the snake’s head moving when it hits the victim?
b) How long does it take the snake’s head to get to the victim?

Q 2. A rocket coasting at 20,000 m/s in deep space fires its engines so that it accelerates at 20 m/s2.
a) How long will it have to keep accelerating to get to a speed of 300,000 m/s?
b) How far will it travel while it is accelerating?

Q 3. A world land speed record was set by Mr. John when he rode a rocket-propelled sled at 283.3 m/s. The
sled was brought to a stop in 1.4s. What acceleration did Mr. John experience?

Q 4. A high-speed train starts from rest and moves with constant acceleration. As it passes a speed trap, a
bored police officer uses a radar gun to measure the train’s speed as 30 m/s. At another speed trap, 160 m
further down the track, another officer measures the train’s speed as 50 m/s.
a) How quickly was the train accelerating?
b) How long did it take to travel the 160 m between speed traps?

Q 5. A boy is inspired by Mr. John’s example to take up rocket sledding. He builds a track so he can get a
modern rocket sled to go from rest up to 445 m/s. If his track is only 225 m long, how quickly will boy (and
sled) have to accelerate to reach the target speed by the end of the track?


Leave a Reply

Name *
Email *