View the step-by-step solution to:

Question

# 1.        A firework leaves the ground with an initial velocity of 45 m/s, travelling

vertically            upwards. It reaches a maximum height of 100m.

At this point the firework fails to explode and falls back down the same vertical path       to the ground.

At any point on its path, the firework has both a velocity and a speed.

(a)  Using the terms vector and scalar, explain the difference between velocity and speed.

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.....................................................................................................................................[3]

(b)      Fig. 1.1 is a graph which shows the height of the firework above the ground during       the first 5 s of its journey.

Fig. 1.1

(i)        Use the information on the graph to

1.         find the time taken for the firework to reach its maximum height above the

ground,

..........................................................................................................................................

2.        describe how the motion of the firework changes over the first 5 s of its                            journey.

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..................................................................................................................................

(ii)       The acceleration of free fall is 10 m/s2 and air resistance on the firework is

negligible. State

1.           the deceleration of the firework as it is rising,

deceleration = ........................................................

2.         the total time taken for the firework to rise 100m and then to fall back to the ground.

time taken = ...........................................................

(iii)      State the velocity with which the falling firework hits the ground.

Velocity                             =................................................................[8]

2.        In an experiment, forces are applied to a spring as shown in Fig. 2.1a. The results of     this experiment are shown in Fig. 2.1b.

Fig. 2.1a                                                                                Fig. 2.1b

(a)      What is the name given to the point marked Q on Fig. 2.1b?

.....................................................................................................................................[1]

(b)       For the part OP of the graph, the spring obeys Hooke's Law.

State what this means.

.........................................................................................................................................

.....................................................................................................................................[1]

(c)      The spring is stretched until the force and extension are shown by the point R                on the graph. Compare how the spring stretches, as shown by the part of the                        graph OQ, with that shown by QR.

.........................................................................................................................................

.....................................................................................................................................[1]

(d)      The part OP of the graph shows the spring stretching according to the                              expression

F = kx.

Use values from the graph to calculate the value of k.

k = ..................................       [2]

3.        Fig. 1.1 shows the path of one drop of water in the jet from a powerful hose.

Fig. 1.1

Fig. 1.2 is a graph of speed against time for the water drop shown in Fig. 1.1.

Fig. 1.2

(a)       Describe the movement of the water drop in the first 4 s after leaving the                         hose.

.........................................................................................................................................

.........................................................................................................................................

.....................................................................................................................................[2]

(b)      Use Fig. 1.2 to find

(i)         the speed of the water leaving the hose,

speed = ........................

(ii)        the time when the speed of the water is least.

time = ........................[2]

(c)      Use values from Fig. 1.2 to calculate the acceleration of the drop as it falls                      back towards the ground. Show your working.

acceleration = ...........................[3]

(d)      Calculate the greatest distance above the ground reached by the drop.

distance = ...........................[3]

4         (a)       State what is meant by the terms

(i)        weight, ....................................................................................................

.............................................................................................................................. [1]

(ii) density. ...........................................................................................................

.............................................................................................................................. [1]

(b)      A student is given a spring balance that has a scale in newtons. The student is              told that the acceleration of free-fall is 10 m/s2.

(i)        Describe how the student could find the mass of an irregular solid                        object...................................................................................................................

..........................................................................................................................................

.................................................................................................................................... [2]

(ii)        Describe how the student could go on to find the density of the object.

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

.................................................................................................................................... [2]

(c)      Fig. 1.1 shows three forces acting on an object of mass 0.5 kg. All three forces                act through the centre of mass of the object.

Fig. 1.1

Calculate

(i)         the magnitude and direction of the resultant force on the object,

magnitude = .................. direction .............................................................. [2]

(ii)       the magnitude of the acceleration of the object.

acceleration =........................   [2]

5.        Fig. 2.1 shows apparatus for investigating moments of forces.Fig. 2.1

The uniform metre rule shown in Fig. 2.1 is in equilibrium.

(a)     Write down two conditions for the metre rule to be in equilibrium.

condition 1 ..........................................................................................................

.........................................................................................................................................

.........................................................................................................................................

condition 2 ...........................................................................................................

.........................................................................................................................................

.................................................................................................................................... [2]

(b)       Show that the value of the reading on the spring balance is 8.0N.              [2]

(c)      The weight of the uniform metre rule is 1.5N.

Calculate the force exerted by the pivot on the metre rule.

magnitude of force = .......................................

direction of force ....................................... [2]

6.        A student investigated the stretching of a spring by hanging various weights from it       and measuring the corresponding extensions. The results are shown below.

(a)       On Fig. 3.1, plot the points from these results. Do not draw a line through the                points yet.                                                                                                      [2]

Fig. 3.1

(b)       The student appears to have made an error in recording one of the results.

Which result is this?

................................................................................................................................... [1]

(c)      Ignoring the incorrect result, draw the best straight line through the remaining points                                                                                                                            [1]

(d)       State and explain whether this spring is obeying Hooke's Law.

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

................................................................................................................................... [2]

(e)      Describe how the graph might be shaped if the student continued to add several more

weights to the spring.

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

................................................................................................................................... [1]

(f)       The student estimates that if he hangs a 45 N load on the spring, the extension will be

920 mm.

Explain why this estimate may be unrealistic.

.........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

................................................................................................................................... [1]

[Total: 8]

7.        (a)       Define acceleration. Explain any symbols in your definition.

..........................................................................................................................................

.....................................................................................................................................[1]

(b)      Fig. 1.1 shows a graph of speed against time for a train. After 100 s the train                   stops at a station.

Fig. 1.1

(i)         For the time interval between 40 s and 100 s, calculate the distance travelled                 by the train.

distance = ..........................................................      [2]

(ii)       The train stops for 80 s, then accelerates to 30 m / s with an acceleration of                     0.60 m / s2. It then travels at constant speed.

Complete the graph for the interval 100 s to 280 s, to show the rest of the

journey, showing your calculations in the space below.

[5]

[Total: 8]

8.        An astronaut has a mass of 65 kg on Earth, where the gravitational field strength is      10 N / kg.

(a)      Calculate the astronaut's weight on Earth.

weight on Earth = ............................................................  [2]

(b)      Complete the following sentence.

The astronaut's weight on Earth is the ........................................................force

between the astronaut and ................................................................... .  [1]

(c)       The astronaut undertakes a Moon landing. On the Moon the gravitational field              strength is 1.6 N / kg.

(i)        State the astronaut's mass on the Moon.

mass = ...............................................................

(ii)       Calculate the weight of the astronaut on the Moon.

weight on Moon = ...............................................................[2]

[Total: 5]

9.                 A sprinter runs a race of 200 m.

Her total time for running the race is 25 s.

Below is a sketch of the speed-time graph for the motion of the sprinter.

speed  (m s-1)

9

u

4

20

25     time (s)

Calculate:

a) The acceleration in the first 4 seconds of the race

.............. (2)

b) The distance covered by the sprinter in the first 20 seconds of the race

c) The value of u

.............. (2)

.............. (3)

10.

Below is a sketch of the speed-time graph of a cyclist moving on a straight road over a 7 second period.

v (m s-1)

5

2

O

3

7

t (s)

Calculate:

a) The acceleration for the first 3 seconds

.............. (2)

b) The distance covered by the cyclist over the 7 second period

.............           (2)

### Why Join Course Hero?

Course Hero has all the homework and study help you need to succeed! We’ve got course-specific notes, study guides, and practice tests along with expert tutors.

• ### -

Study Documents

Find the best study resources around, tagged to your specific courses. Share your own to gain free Course Hero access.

Browse Documents