general physics

Question 1

4 vector

Answer 1

force, weight, velocity, acceleration, momentum,
electric field strength and gravitational field
strength

Question 2

4 scalar

Answer 2

distance, speed, time, mass, energy and
temperature

Question 3

Define mass

Answer 3

measure of the quantity
of matter in an object at rest relative to the
observer

Question 4

define weight

Answer 4

gravitational force on an
object that has mass

Question 5

gravity [3]

Answer 5

3) g =
W / m
1) force per
unit mass
2) equivalent to the
acceleration of free fall

Question 6

How is weight (mass) compared

Answer 6

by using a balance

Question 7

Define density

Answer 7

mass per unit volume
ρ = m / V

Question 8

Determine whether an object floats based on
density data

Answer 8

Object will float if its density is less than the density of the solution it is in

Question 9

is weight a force

Answer 9

true

Question 10

Si units for gravitational field strength

Answer 10

(N/kg)

Question 11

SI unit for weight

Answer 11

N

Question 12

SI unit for mass

Answer 12

kg

Question 13

SI unit for density

Answer 13

kg/m^3

Question 14

It is incorrect to describe the circular motion as having constant velocity

Answer 14

The direction of motion is changing OR constant velocity must be in a straight line

Question 15

A force is required to maintain circular motion because [2]

Answer 15

A resultant force is needed for an object to change direction OR without a resultant force the object would continue moving at a constant velocity in a straight line; [1 mark]
The car is moving in a circle so it is changing direction, so the velocity is changing / the car is accelerating; [1 mark]

Question 16

For objects in circular motion, the force acts

Answer 16

Towards the centre of the circle OR at right angles to the motion

Question 17

The name of the inward acting force for the car in circular motion on the track

Answer 17

Friction; [1 mark]
[Total: 1 mark]

Remember that centripetal force is not a force in its own right but is the force that keeps an object moving in a circle.

If there was no friction between the car tyres and the track, the car would not be able to move in a circle. The friction acts towards the centre of it and is the centripetal force in this situation.

Question 18

How would you find the speed of the train at time t = 100 s on a distance time graph [2]

Answer 18

1) Draw tangent
2) Calculate Change in distance / change in time (gradient)

it needs to be on exactly 100s so we do it precisely

Question 19

What happens to the acceleration of a straight line on a distance time graph?

Answer 19

It becomes 0
Because acceleration is only produced when velocity changes

Question 20

Define deceleration

Answer 20

Negative acceleration

Question 21

The initial acceleration of the train is 0.75 m/s .
Calculate there sultant force that acts on thet rain at this time. The train is 5.6 × 10^5 kg

Answer 21

F=ma
F= 5.6x10^5 * 0.75
= 4.2 × 10^5 N

Question 22

Define acceleration

Answer 22

Rate of change of velocity; [1 mark]
OR

fraction numerator C h a n g e space o f space v e l o c i t y over denominator T i m e end fraction [1 mark]

Question 23

Centre of gravity define

Answer 23

Place where all the weight acts

Question 24

2 methods of generating electrical power not from the sun

Answer 24

1) Geothermal
2) Nuclear