Show:
motion
energy
velocity
distance
speed
100
what is motion?
A change in position compared to a reference point.
100
What is an object's speed if it is a slow moving object?
low speed
100
What is the speed of a jet plane that travels 528 meters in 4 seconds?
d=vt d=528 m t=4 sec solving for v, v=d/t, v=132 m/sec.
100
what is distance?
is the length of a path between to points
100
the object accelerates
when an object increases it does what?
200
The object does not appear to be staying in one place. Or, it is moving if it's distance from another object is changing.
How do you know if an object is moving?
200
The kinetic energy of an object depends on both what?
mass and speed
200
What is the speed of a rocket that travels 9000 meters in 12.12 seconds?
d=9000 m t=12.12 sec. solving for v, v=d/t, v=742.57 m/sec.
200
An aeroplane covers a certain distance at a speed of 240 kmph in 5 hours. To cover the same distance in 1 hours, it must travel at a speed of:
Answer: Option D Explanation: Distance = (240 x 5) = 1200 km. Speed = Distance/Time Speed = 1200/(5/3) km/hr. [We can write 1 hours as 5/3 hours] Required speed = 1200 x 3 km/hr = 720 km/hr. 5
200
what is speed?
How fast an object changes its position;rate.
300
How do you know if something is moving?
Compare it to a reference point.
300
When a top spins on the ground, some of it's kinetic energy converts to?
Thermal energy
300
What does velocity include?
A speed and direction.
300
If a person walks at 14 km/hr instead of 10 km/hr, he would have walked 20 km more. The actual distance travelled by him is:
Let speed of the car be x kmph. Then, speed of the train = 150 x = 3 x kmph. 100 2 75 - 75 = 125 x (3/2)x 10 x 60 75 - 50 = 5 x x 24 x = 25 x24 = 120 kmph.
300
when it's changes direction.
when does an object change it's speed?
400
A scooter travels a distance of 600 m in 20 seconds southwards. (a) What is the speed of the scooter? (b) What is the velocity of the scooter?
(a) Speed = = 30 m/s (b) Velocity of the scooter = 30 m/s due south.
400
What happen when an object/living thing does work on another object?
some of it's energy transfers to the other object
400
What is the speed of a walking person in m/s if the person travels 1000 m in 20 minutes?
d=vt d=1000m t=20 min.(60 sec.) =1200 sec. min solving for v, v=d/t, v=0.83 m/sec.
400
Two friends A and B run around a circular track of length 510 metres, starting from the same point, simultaneously and in the same direction. A who runs faster laps B in the middle of the 5th round. If A and B were to run a 3 km race long race, how much start, in terms of distance, should A give B so that they finish the race in a dead heat? A. 545.45 metres B. 666.67 metres C. 857.14 metres D. Cannot be determined
Answer – (B) Solution: A and B run around a circular track. A laps B in the middle of the 5th lap. i.e. when A has run four and a half laps he has covered a distance which is 1 lap greater than that covered by B's. Therefore, when A runs 9 2 laps, B runs 7 2 laps. This is same as saying when A runs 9 laps, B runs 7 laps. i.e in a race that is 9 laps long, A can give B a start of 2 laps. So, if the race is of 3000 metres long, then A can give B a start of ( 2 9 )×3000= 666.67 metres. The information with regard to the length of the circular track is redundant information.
400
What is the forumla?
speed=D/T
500
A machine arm moves in a left-to-right-to-left motion. It moves twice as fast to the right as it does to the left. A complete left-to-right-to-left cycle takes 3 seconds to complete. The rate of travel when moving to the left is 10 centimeters per second (c/s). How far does the machine arm move in each direction?
Motion to the left: let a represent the time d = rt = 10a Motion to the right: let b represent the time a + b = 3 b = 3 - a the rate of travel to the right is twice that of the rate of travel to the left: r = 2(10) = 20 c/s d = rt = 20b = 20(3 - a) The two distances are equal: 10a = 20(3 -a) 10a = 60 - 20a 30a = 60 a = 2 seconds b = 3 - a = 3 - 2 = 1 second d = 10a = 20b = 10(2) = 20(1) = 20 centimeters
500
Any object that rises or falls experiences a change in its what?
Kinetic and gravitational potential energy.
500
How do you make a change in velocity?
You either change the direction, speed, or both.
500
A person crosses a 600 m long street in 5 minutes. What is his speed in km per hour?
Explanation: Speed = 600 m/sec. 5 x 60 = 2 m/sec. Converting m/sec to km/hr (see important formulas section) = 2 x 18 km/hr 5 = 7.2 km/hr.
500
What is an object's speed if it has no movement ?
zero speed