u = ?m/s
d = 38m
a = 4.0m/s/s
t =4
Now place the above values into the formula and transpose to make it equal
to "u", the initial speed.
Click to hide
u = 30m/s
d = ?m
a = 8.0m/s/s
t =23s
Now place the above values into the formula and transpose to make it equal
to "d", the the distance travelled.
Click to hide
u = 0m/s(standing star)
d = 80m
a = 0.8m/s/s
t =?
Now place the above values into the formula and transpose to make it equal
to "t", the time taken.
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u = ?m/s
d = 180m
a = 1.2m/s/s
t =14.4s
Now place the above values into the formula and transpose to make it equal
to "u", the initial speed.
Click to hide
u = ?m/s
d = 16m
a =-5.0m/s/s
t =4s
Now place the above values into the formula and transpose to make it equal
to "u", the initial speed.
Click to hide
u = 0m/s(starts from rest)
d = 100m
a = ?m/s/s
t =5s
Now place the above values into the formula and transpose to make it equal
to "a", the acceleration
.Click to hide
u = 0m/s(it starts from rest
as it hovers)
d = 3000m
a = 9.8m/s/s
t =?
Now place the above values into the formula and transpose to make it equal
to "u", the initial speed.
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First - convert the speed of
the car from km/hr to m/s
Divide the 90km/hr by 3.6 = 25m/s
u = 25m/s
d = 60m
a = ?m/s/s
t = 5s
Now place the above values into the formula and transpose to make it equal
to "a", the acceleration.
Click to hide
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Straight line formulae. |
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The steps you should follow for each example are: Step 1 - collect the data Step 2 - choose the appropriate formula Step 3 - give each pronumeral its respective value Step 3 - solve for the required variable. |
v
= Final velocity u= Initial velocity a = Acceleration t = Time. d = Distance |
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Exercise How long does it take for a car to cover 40m from a standing start, with a constant acceleration of 4.0m/s/s?
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Data
u = 0m/s(Standing
start) |
Solution
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| A
ball is thrown in the air with an unknown initial velocity. 4 seconds after
the ball is thrown its height is measured at 38m. With what initial velocity
was the ball thrown? g = 9.8m/s/s |
Clue |
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| A car passes a checkpoint at 30m/s when the driver accelerates at 8m/s/s until he reaches the next checkpoint 23 seconds later. How far apart are the checkpoints. |
Clue |
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| A cyclist accelerates from a standing start at 0.8m/s/s until she reaches the FINISH line 80m away. How long does it take her to cover 80m? | Clue |
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| A cyclist passes the START line with an unknown velocity. He accelerates at 1.2m/s/s until he reaches the FINISH line 180m away. The time he took to cover the 180m was 14.4 seconds. What was his initial velocity as he crossed the START line? | Clue |
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| A bike brakes with a constant acceleration of -5m/s/s. It takes 16m to stop and 4 seconds elapsed from the time the brakes were applied to the moment the bike stopped. What speed was the bike travelling at? | Clue |
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| What is the acceleration of a bus if it starts from rest and covers 100m in 5 seconds. | Clue |
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How long will it take for a 30 ton spacecraft to free fall onto the surface of an unknown planet, identical to that of Earth but with no atmosphere, if it hovers 3km above the surface before falling. g =9.8m/s/s |
Clue |
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| A car travelling at 90km/hr applies its brakes and travels a further 60m in 5 seconds before coming to rest. What was the deceleration of the car? | Clue |
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