When a body is accelerating, the resultant force acting on it...
Transcript of When a body is accelerating, the resultant force acting on it...
When a body is accelerating, the resultant force acting on it is equal to its A. change of momentum. B. rate of change of momentum. C. acceleration per unit of mass. D. rate of change of kinetic energy.
A trolley of mass 1.5 kg is pulled along a
horizontal table by a force of 5.0N.
force 5.0N
The frictional force acting on the trolley is 0.50N.
The acceleration of the trolley is
A. 0.30 m s–2.
B. 0.33 m s–2.
C. 3.0 m s–2.
D. 3.3 m s–2.
A body moving along a straight-line has mass 3.0 kg and kinetic energy 24 J. The motion is then opposed by a net force of 4.0 N. The body will come to rest after travelling a distance of A. 2.0 m. B. 6.0 m. C. 8.0 m. D. 12 m.
In an experiment to
measure the
acceleration of free fall
at the surface of the
Earth, the following
results were obtained.
These results are
Acceleration of free fall / m s–2
7.69
7.70
7.69
7.68
7.70
A. accurate and precise.
B. inaccurate but precise.
C. accurate but imprecise.
D. inaccurate and imprecise..
Which of the following is the condition for a body to be in translational equilibrium? A. The resultant force on the body in any
direction is zero. B. The velocity of the body in any direction is
zero. C. No external force is acting on the body. D. No work is done on the body.
The number of heartbeats of a person at rest in one hour, to the nearest order of magnitude is A. 101. B. 102. C. 103. D. 105.
Natalie measures the mass and speed of a glider. The percentage uncertainty in her measurement of the mass is 3% and in the measurement of the speed is 10%. Her calculated value of the kinetic energy of the glider will have an uncertainty of A. 30%. B. 23%. C. 13%. D. 10%.
A ball is released from rest near the surface of the Moon. Which one of the following quantities increases at a constant rate? A. Only distance fallen B. Only speed C. Only speed and distance fallen D. Only speed and acceleration
An object is moving at constant velocity. Which one of the following quantities must have zero magnitude? A. Weight of object B. Momentum of object C. Kinetic energy of object D. Resultant force on object
A bus is travelling at a constant speed of 6.2 ms-1
along a section of road that is inclined at an angle
of 6.0° to the horizontal.
The total output power of the engine of the bus is 70 kW and the efficiency of the engine is 35 %. Calculate the input power to the engine.
. B. h. C. h2. D. h3.
The gravitational potential energy of the water
stored in the basin between a high tide and a low
tide is proportional to
A.
h
Water is contained in a tidal basin behind a
dam. The water has a depth h at high tide and
zero at low tide, as shown in the diagram.
A nuclear power station produces 10 GW of electrical power. The power generated by the nuclear reactions in the core of the reactor is 25 GW. The efficiency of the power station is A. 15 %. B. 35 %. C. 40 %. D. 60 %.
Two lengths, a and b, are measured
to be 51±1 cm and 49±1 cm
respectively. In which of the following
quantities is the percentage
uncertainty the largest?
A. a + b B. a – b
C. a × b D.
b
a
In a ride in a pleasure park, a carriage of mass 450 kg is
travelling horizontally at a speed of 18 m s–1. It passes
through a shallow tank containing stationary water. The
tank is of length 9.3 m. The carriage leaves the tank at a
speed of 13 m s–1. 18 m s
carriage, mass 450 kg
9.3m
water-tank 13 m s–1–1
As the carriage passes through the tank, the carriage
loses momentum and causes some water to be pushed
forwards with a speed of 19 m s–1 in the direction of
motion of the carriage.
For the carriage passing through the water-tank, find
the magnitude of its total change in momentum.
2250 Ns
In a ride in a pleasure park, a carriage of mass 450 kg is
travelling horizontally at a speed of 18 m s–1. It passes
through a shallow tank containing stationary water. The
tank is of length 9.3 m. The carriage leaves the tank at a
speed of 13 m s–1. 18 m s
carriage, mass 450 kg
9.3m
water-tank 13 m s–1–1
As the carriage passes through the tank, the carriage loses
momentum and causes some water to be pushed forwards with a
speed of 19 m s–1 in the direction of motion of the carriage.
Knowing the total change in momentum of the carriage passing
through the tank is 2250 Ns, find the mass of water moved in the
direction of motion of the carriage.
shape of curve wrong / curve does not go through zero;
.inv
The maximum electrical power generated by a wind
turbine, Pout, was measured over a range of incident
wind speeds, vin.
The graph below shows the
variation with vin of Pout.
Uncertainties for the data
are not shown.
It is suggested that Pout
is proportional to
State one reason why the
best fit line does not
support this hypothesis.
The graph shows the variation with force F of the extension s of a spring. The work done in changing the extension of the spring from 3.0 cm to 6.0 cm is A. 15 N cm. B. 30 N cm. C. 45 N cm. D. 60 N cm.
On the sketch graph below, label with the letter A a point at which the acceleration of the pendulum bob is a maximum.
On the sketch graph below, label with the letter V a point at which the speed of the pendulum bob is a maximum.